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Sample records for african plate relative

  1. The nature and location of the plate boundary between the Anatolian and African plates

    NASA Astrophysics Data System (ADS)

    deǧer Özbakır, Ali; Wortel, Rinus; Govers, Rob

    2010-05-01

    Overall convergence of the African, Arabian and Eurasian plates, and the westward escape of Anatolia has resulted in an evolving plate boundary zone since the Miocene. In the Eastern Mediterranean, the current location and nature of the plate boundary between the Anatolian and the African plates is difficult to trace due to the scattered crustal earthquakes, and the absence of deeper earthquakes. In this study we aim to better constrain the nature and the location of the plate boundary. GPS-derived velocity field and stresses from earthquake mechanism solutions comprise the datasets which short time scale (elastic) models can be compared to. We model the stresses and deformation on the overriding plate by incorporating convergence of Africa and Arabia towards stable Eurasia, and rollback of the Hellenic trench. Investigation of the plate boundary consists of constraining the directions of motions over the segments which make up the boundary. We assume various types and locations for the plate boundary within the observational limits. We use a spherical plane stress finite element model to test these possibilities. We find that stresses and displacements are sensitive to both the location and the nature of the plate boundary. We obtain the minimum misfit with the data in a model where we assume the following: (1) the segment between Hellenic and the Cyprus arcs have both down-dip and fault parallel motions, (2) the connection between the Cyprus arc and Arabia--Eurasia collision zone is pure strike-slip. In all our models, an extra pull force on Anatolia is required to explain the high velocities in southwest Anatolia. This force may be related to return flow around the lateral edge of the Aegean slab.

  2. Plio-Quaternary paleostresses in the Atlantic passive margin of the Moroccan Meseta: Influence of the Central Rif escape tectonics related to Eurasian-African plate convergence

    NASA Astrophysics Data System (ADS)

    Chabli, Ahmed; Chalouan, Ahmed; Akil, Mostapha; Galindo-Zaldívar, Jesús; Ruano, Patricia; Sanz de Galdeano, Carlos; López-Garrido, Angel Carlos; Marín-Lechado, Carlos; Pedrera, Antonio

    2014-07-01

    The Atlantic Moroccan Meseta margin is affected by far field recent tectonic stresses. The basement belongs to the variscan orogen and was deformed by hercynian folding and metamorphism followed by a post-Permian erosional stage, producing the flat paleorelief of the region. Tabular Mesozoic and Mio-Plio-Quaternary deposits locally cover the Meseta, which has undergone recent uplift, while north of Rabat the subsidence continues in the Gharb basin, constituting the foreland basin of the Rif Cordillera. The Plio-Quaternary sedimentary cover of the Moroccan Meseta, mainly formed by aeolian and marine terraces deposits, is affected by brittle deformations (joints and small-scale faults) that evidence that this region - considered up to date as stable - is affected by the far field stresses. Striated faults are recognized in the oldest Plio-Quaternary deposits and show strike-slip and normal kinematics, while joints affect up to the most recent sediments. Paleostress may be sorted into extensional, only affecting Rabat sector, and three main compressive groups deforming whole the region: (1) ENE-WSW to ESE-WNW compression; (2) NNW-SSE to NE-SW compression and (3) NNE-SSW compression. These stresses can be attributed mainly to the NW-SE oriented Eurasian-African plate convergence in the western Mediterranean and the escape toward the SW of the Rif Cordillera. Local paleostress deviations may be related to basement fault reactivation. These new results reveal the tectonic instability during Plio-Quaternary of the Moroccan Meseta margin in contrast to the standard passive margins, generally considered stable.

  3. Current plate velocities relative to the hotspots incorporating the NUVEL-1 global plate motion model

    SciTech Connect

    Gripp, A.E.; Gordon, R.G. )

    1990-07-01

    NUVEL-1 is a new global model of current relative plate velocities which differ significantly from those of prior models. Here the authors incorporate NUVEL-1 into HS2-NUVEL1, a new global model of plate velocities relative to the hotspots. HS2-NUVEL1 was determined from the hotspot data and errors used by Minster and Jordan (1978) to determine AM1-2, which is their model of plate velocities relative to the hotspots. AM1-2 is consistent with Minster and Jordan's relative plate velocity model RM2. Here the authors compare HS2-NUVEL1 with AM1-2 and examine how their differences relate to differences between NUVEL-1 and RM2. HS2-NUVEL1 plate velocities relative to the hotspots are mainly similar to those of AM1-2. Minor differences between the two models include the following: (1) in HS2-NUVEL1 the speed of the partly continental, apparently non-subducting Indian plate is greater than that of the purely oceanic, subducting Nazca plate; (2) in places the direction of motion of the African, Antarctic, Arabian, Australian, Caribbean, Cocos, Eurasian, North American, and South American plates differs between models by more than 10{degree}; (3) in places the speed of the Australian, Caribbean, Cocos, Indian, and Nazca plates differs between models by more than 8 mm/yr. Although 27 of the 30 RM2 Euler vectors differ with 95% confidence from those of NUVEL-1, only the AM1-2 Arabia-hotspot and India-hotspot Euler vectors differ with 95% confidence from those of HS2-NUVEL1. Thus, substituting NUVEL-1 for RM2 in the inversion for plate velocities relative to the hotspots changes few Euler vectors significantly, presumably because the uncertainty in the velocity of a plate relative to the hotspots is much greater than the uncertainty in its velocity relative to other plates.

  4. Images may show start of European-African plate collision

    NASA Astrophysics Data System (ADS)

    Mascle, J.; Huguen, C.; Benkhelil, J.; Chamot-Rooke, N.; Chaumillon, E.; Foucher, J. P.; Griboulard, R.; Kopf, A.; Lamarche, G.; Volkonskaia, A.; Woodside, J.; Zitter, T.

    Aspects of the initial stages of a collision between European and African plates may have been documented in a geophysical survey of the central Mediterranean Ridge (MR) conducted last year. The idea of an incipient collision was first suggested by Finetti [1976],and details of the seafloor and tectonic deformation along the MR, revealed for the first time in the survey, seem to point in that direction.A unique opportunity may therefore exist for studying the beginnings of such a collision—between the passive margin of a major plate (Africa) acting as a continental indenter against the active margin of another plate (Europe). More wide angle data, deep penetrating multichannel seismic data, and drilling data are crucial to better assess the nature and the architecture of the underlying lithosphere, the styles of sedimentary deformation, and the consequences on fluid releases. Such data will make it possible to establish, or reject, a geodynamic collision model.

  5. Determination of recent horizontal crustal movements and deformations of African and Eurasian plates in western Mediterranean region using geodetic-GPS computations extended to 2006 (from 1997) related to NAFREF and AFREF frames.

    NASA Astrophysics Data System (ADS)

    Azzouzi, R.

    2009-04-01

    Determination of recent horizontal crustal movements and deformations of African and Eurasian plates in western Mediterranean region using geodetic-GPS computations extended to 2006 (from 1997) related to NAFREF and AFREF frames. By: R. Azzouzi*, M. Ettarid*, El H. Semlali*, et A. Rimi+ * Filière de Formation en Topographie Institut Agronomique et Vétérinaire Hassan II B.P. 6202 Rabat-Instituts MAROC + Département de la Physique du Globe Université Mohammed V Rabat MAROC This study focus on the use of the geodetic spatial technique GPS for geodynamic purposes generally in the Western Mediterranean area and particularly in Morocco. It aims to exploit this technique first to determine the geodetic coordinates on some western Mediterranean sites. And also this technique is used to detect and to determine movements cross the boundary line between the two African and Eurasian crustal plates on some well chosen GPS-Geodynamics sites. It will allow us also to estimate crustal dynamic parameters of tension that results. These parameters are linked to deformations of terrestrial crust in the region. They are also associated with tectonic constraints of the study area. The usefulness of repeated measurements of these elements, the estimate of displacements and the determination of their temporal rates is indisputable. Indeed, sismo-tectonique studies allow a good knowledge of the of earthquake processes, their frequency their amplitude and even of their prediction in the world in general and in Moroccan area especially. They allow also contributing to guarantee more security for all most important management projects, as projects of building great works (dams, bridges, nuclear centrals). And also as preliminary study, for the most important joint-project between Europe and Africa through the Strait of Gibraltar. For our application, 23 GPS monitoring stations under the ITRF2000 reference frame are chosen in Eurasian and African plates. The sites are located around the

  6. Cretaceous to present kinematics of the Indian, African and Seychelles plates

    NASA Astrophysics Data System (ADS)

    Eagles, Graeme; Hoang, Ha H.

    2014-01-01

    An iterative inverse model of seafloor spreading data from the Mascarene and Madagascar basins and the flanks of the Carlsberg Ridge describes a continuous history of Indian-African Plate divergence since 84 Ma. Visual-fit modelling of conjugate magnetic anomaly data from near the Seychelles platform and Laxmi Ridge documents rapid rotation of a Seychelles Plate about a nearby Euler pole in Palaeocene times. As the Euler pole migrated during this rotation, the Amirante Trench on the western side of the plate accommodated first convergence and later divergence with the African Plate. The unusual present-day morphology of the Amirante Trench and neighbouring Amirante Banks can be related to crustal thickening by thrusting and folding during the convergent phase and the subsequent development of a spreading centre with a median valley during the divergent phase. The model fits FZ trends in the north Arabian and east Somali basins, suggesting that they formed in India-Africa Plate divergence. Seafloor fabric in and between the basins shows that they initially hosted a segmented spreading ridge that accommodated slow plate divergence until 71-69 Ma, and that upon arrival of the Deccan-Réunion plume and an increase to faster plate divergence rates in the period 69-65 Ma, segments of the ridge lengthened and propagated. Ridge propagation into the Indian continental margin led first to the formation of the Laxmi Basin, which accompanied extensive volcanism onshore at the Deccan Traps and offshore at the Saurashtra High and Somnath Ridge. A second propagation episode initiated the ancestral Carlsberg Ridge at which Seychelles-India and India-Africa Plate motions were accommodated. With the completion of this propagation, the plate boundaries in the Mascarene Basin were abandoned. Seafloor spreading between this time and the present has been accommodated solely at the Carlsberg Ridge.

  7. The African Plate: A history of oceanic crust accretion and subduction since the Jurassic

    NASA Astrophysics Data System (ADS)

    Gaina, C.; Torsvik, T. H.; Labails, C.; van Hinsbergen, D.; Werner, S.; Medvedev, S.

    2012-04-01

    Initially part of Gondwana and Pangea, and now surrounded almost entirely by spreading centres, the African plate moved relatively slowly for the last 200 million years. Yet both Africa's cratons and passive margins were affected by tectonic stresses developed at distant plate boundaries. Moreover, the African plate was partly underlain by hot mantle (at least for the last 300 Ma) - either a series of hotspots or a superswell, or both - that contributed to episodic volcanism, basin-swell topography, and consequent sediment deposition, erosion, and structural deformation. A systematic study of the African plate boundaries since the opening of surrounding oceanic basins is presently lacking. This is mainly because geophysical data are sparse and there are still controversies regarding the ages of oceanic crust. The publication of individual geophysical datasets and more recently, global Digital Map of Magnetic Anomalies (WDMAM, EMAG2) prompted us to systematically reconstruct the ages and extent of oceanic crust around Africa for the last 200 Ma. Location of Continent Ocean Boundary/Continent Ocean Transition and older oceanic crust (Jurassic and Cretaceous) are updates in the light of gravity, magnetic and seismic data and models of passive margin formation. Reconstructed NeoTethys oceanic crust is based on a new model of microcontinent and intr-oceanic subduction zone evolution in this area.The new set of oceanic palaeo-age grid models constitutes the basis for estimating the dynamics of oceanic crust through time and will be used as input for quantifying the paleo-ridge push and slab pull that contributed to the African plate palaeo-stresses and had the potential to influence the formation of sedimentary basins.

  8. Long-term CGPS Measurements (1995-2008) in the Hellenic Deformation Zone Between the Eurasian and African Plates

    NASA Astrophysics Data System (ADS)

    Kahle, H.; Mueller, M. D.; Geiger, A.; Veis, G.; Billiris, H.; Paradissis, D.; Felekis, S.; Galanis, D.

    2008-12-01

    The Eastern Mediterranean forms the seismically most active region of the Alpine-Mediterranean plate boundary. It is characterized by the collision between the Eurasian and African plates. The collision is closely related to continental subduction and formation of the pronounced Hellenic trench system. In addition to the relatively slow CCW rotation of the African plate, rapid motion of the Anatolian-Aegean region is encountered, directed towards west-southwest, reaching velocities of up to 4 cm/yr along the Hellenic arc, relative to Eurasia. A long-term record of continuous GPS (CGPS) time series (1995-2008) and campaign- type GPS measurements (1991-2008) will be presented. The data has been analyzed to derive rates of plate and microplate motion and to study the strain rate field in the deforming zone between the Eurasian and African plates. This includes the deformation belt extending from the Ionian islands to the North Aegean Sea, Greece. While the Ionian islands are characterized by the Kephalonia fault zone which terminates the subduction of the Hellenic arc the most important feature in the North Aegean sea is the North Aegean trough which is considered to form the western continuation of the North Anatolian Fault Zone. Most recent GPS results will be presented for both regions and discussed in terms of ongoing deformation processes including dextral faulting and transtension, encountered in the northern Hellenic boundary region between the Eurasian and African plates.

  9. Convection pattern and stress system under the African plate

    NASA Technical Reports Server (NTRS)

    Liu, H.-S.

    1977-01-01

    Studies on tectonic forces from satellite-derived gravity data have revealed a subcrustal stress system which provides a unifying mechanism for uplift, depression, rifting, plate motion and ore formation in Africa. The subcrustal stresses are due to mantle convection. Seismicity, volcanicity and kimberlite magmatism in Africa and the development of the African tectonic and magnetic features are explained in terms of this single stress system. The tensional stress fields in the crust exerted by the upwelling mantle flows are shown to be regions of structural kinship characterized by major concentration of mineral deposits. It is probable that the space techniques are capable of detecting and determining the tectonic forces in the crust of Africa.

  10. Cycloid kinematics of relative plate motion

    SciTech Connect

    Cronin, V.S.

    1987-11-01

    The trajectory of a point on one plate as observed from another plate is generally a complex curve and not a small circle around a single axis of relative motion, as is commonly assumed. The shape of the relative-motion path is given the general name spherical cycloid because of its morphological similarity to cycloid planetary trajectories described by early astronomers. The cycloid relative-motion model predicts that the following phenomena occur during finite displacements: (1) the relative velocity and the curvature of the trajectory of a point on one plate relative to another plate varies systematically; (2) plates wobble relative to one another; and (3) the angle of convergence and/or divergence varies systematically along the length of any given transform fault. The small-circle relative-motion model, whereby transform faults have been considered lines of pure slip along which crust is conserved, is not generally valid for finite relative displacements.

  11. Computing relative plate velocities: a primer

    SciTech Connect

    Bevis, M.

    1987-08-01

    Standard models of present-day plate motions are framed in terms of rates and poles of rotation, in accordance with the well-known theorem due to Euler. This article shows how computation of relative plate velocities from such models can be viewed as a simple problem in spherical trigonometry. A FORTRAN subroutine is provided to perform the necessary computations.

  12. Phanerozoic evolution of plants on the African plate

    NASA Astrophysics Data System (ADS)

    Burgoyne, P. M.; van Wyk, A. E.; Anderson, J. M.; Schrire, B. D.

    2005-10-01

    The Phanerozoic has witnessed major changes, with Africa being an integral part of supercontinental landmass agglomeration forming Gondwana, its amalgamation with smaller landmasses to form Pangaea, and later disintegrating to form the existing continents. At the same time climates, atmosphere, oceanic circulation and tectonic plates shifted. During this upheaval, life was evolving and organisms were adapting and with higher diversity came more ecological interactions, creating more habitats and thus influencing more biological radiation. Plants became more complex, developing from unicellular to multicellular organisms. Moving from water onto land, plants had to cope with desiccation, and features evolved enabling them to do this. Patterns of Phanerozoic plant evolution are strongly driven by major changes in the physical environment, most notably continental drift, climate change and bolide impacts, precipitating massive volcanism and other effects leading to mass global extinctions. The products of this evolution were early land plants during Silurian and Devonian times. Subjected to extinction events and environmental changes, these early plants gave rise to the pteridophytes reaching their diversity peak during the Carboniferous and Permian. After the demise of the pteridophytes, the gymnosperms dominated during the Triassic and Jurassic, followed by the emergence of the angiosperms in the Cretaceous. This melange of factors has produced the present plant diversity on earth, which we will examine in context of the African flora. Plant diversification in Gondwana and Laurasia will be covered focussing on Africa, while factors affecting the vegetation and species composition of the present flora will be discussed.

  13. Geodynamics of the Indian Lithospheric Plate relative to the neighbouring Plates as revealed by Space Geodetic Measurements

    NASA Astrophysics Data System (ADS)

    Krishna, S.; Mathew, J.; Majumdar, R.; Roy, P.; Vinod Kumar, K.

    2014-11-01

    The Indian Plate is highly dynamic in nature which in turn makes the Indo-Eurassian collision zone the foci of most of the historic large magnitude earthquakes. Processing of positional information from continuously observing reference stations is one of the space based geodetic techniques used globally and nationally to understand the crustal dynamics. The present study evaluates the dynamic nature of the Indian plate relative to its adjoining plates using the permanent GPS data (2011 to 2013) of 12 International GNSS Service (IGS), which are spread across the Indian, Eurassian, Australian, Somaliyan and African plates. The data processing was carried out using GAMIT/GLOBK software. The results indicate that the average velocity for the two IGS stations on the Indian Plate (Hyderabad and Bangalore) is 54.25 mm/year towards NE in the ITRF-2008 reference frame. The relative velocity of various stations with respect to the Indian plate has been estimated using the Bangalore station and has been found that the stations in the Eurasian plate (Lhasa, Urumqi, Bishkek and Kitab) are moving with velocity ranging from 25 to 33 mm/year in the SE direction resulting in compressional interaction with the Indian plate. This study reveals and confirms to the previous studies that the Indian- Eurassian-Australian Plates are moving at different relative velocities leading to compressional regimes at their margins leading to seismicity in these zones.

  14. African American Preschoolers' Language, Emergent Literacy Skills, and Use of African American English: A Complex Relation

    ERIC Educational Resources Information Center

    Connor, Carol McDonald; Craig, Holly K.

    2006-01-01

    Purpose: This study examined the relation between African American preschoolers' use of African American English (AAE) and their language and emergent literacy skills in an effort to better understand the perplexing and persistent difficulties many African American children experience learning to read proficiently. Method: African American…

  15. Caribbean tectonics and relative plate motions

    NASA Technical Reports Server (NTRS)

    Burke, K.; Dewey, J. F.; Cooper, C.; Mann, P.; Pindell, J. L.

    1984-01-01

    During the last century, three different ways of interpreting the tectonic evolution of the Gulf of Mexico and the Caribbean have been proposed, taking into account the Bailey Willis School of a permanent pre-Jurassic deep sea basin, the Edward Suess School of a subsided continental terrain, and the Alfred Wegener School of continental separation. The present investigation is concerned with an outline of an interpretation which follows that of Pindell and Dewey (1982). An attempt is made to point out ways in which the advanced hypotheses can be tested. The fit of Africa, North America, and South America is considered along with aspects of relative motion between North and South America since the early Jurasic. Attention is given to a framework for reconstructing Caribbean plate evolution, the evolution of the Caribbean, the plate boundary zones of the northern and southern Caribbean, and the active deformation of the Caribbean plate.

  16. The satellite magnetic anomaly of Ahaggar - Evidence for African Plate motion

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Brown, C. R.

    1985-01-01

    The Ahaggar volcanic province of North Central Africa is considered a region of excess heat flow (hot spot) and hence elevated Curie isotherm. Using a modified version of the Parker FFT potential field representation, magnetic signals were calculated at Magsat altitudes for models in which the African Plate is both fixed and moving. The moving-plate model extends the Curie isotherm anomaly in the direction of plate motion and provides a satisfactory match to vertical component anomaly data when the magnitude of plate velocity is 0.75 cm/yr. Although the signal levels are marginal for the scalar component anomalies of this region, the same model provides an adequate match to this data set and is clearly preferable to a fixed-plate model.

  17. Phanerozoic within-plate magmatism of North Asia: Absolute paleogeographic reconstructions of the African large low-shear-velocity province

    NASA Astrophysics Data System (ADS)

    Kuz'min, M. I.; Yarmolyuk, V. V.; Kravchinsky, V. A.

    2011-11-01

    The phanerozoic within-plate magmatism of Siberia is reviewed. The large igneous provinces (LIPs) consecutively arising in the Siberian Craton are outlined: the Altai-Sayan LIP, which operated most actively 400-375 Ma ago, the Vilyui LIP, which was formed from the Middle Devonian to the Early Carboniferous, included; the Barguzin-Vitim LIP (305-275 Ma); the Late Paleozoic Rift System of Central Asia (318-250 Ma); the Siberian flood basalt (trap) province and the West Siberian rift system (250-247 Ma); and the East Mongolian-West Transbaikal LIP (230-195 Ma), as well as a number of Late-Mesozoic and Cenozoic rift zones and autonomous volcanic fields formed over the last 160 Ma. The trace-element and isotopic characteristics of the igneous rocks of the above provinces are reviewed; their mantle origin is substantiated and the prevalence of PREMA, EM2, and EM1 mantle magma sources are shown. The paleogeographic reconstructions based on paleomagnetic data assume that the Iceland hot spot was situated beneath the Siberian flood basalts 250 Ma ago and that the mantle plumes retained a relatively stable position irrespective of the movements of the lithospheric plates. At present, the Iceland hot spot occurs near the northern boundary of the African large low shear velocity province (LLSVP). It is suggested that the within-plate Phanerozoic magmatism of Siberia was related to the drift of the continent above the hot spots of the African LLSVP.

  18. Plate Kinematic model of the NW Indian Ocean and derived regional stress history of the East African Margin

    NASA Astrophysics Data System (ADS)

    Tuck-Martin, Amy; Adam, Jürgen; Eagles, Graeme

    2015-04-01

    Starting with the break up of Gondwana, the northwest Indian Ocean and its continental margins in Madagascar, East Africa and western India formed by divergence of the African and Indian plates and were shaped by a complicated sequence of plate boundary relocations, ridge propagation events, and the independent movement of the Seychelles microplate. As a result, attempts to reconcile the different plate-tectonic components and processes into a coherent kinematic model have so far been unsatisfactory. A new high-resolution plate kinematic model has been produced in an attempt to solve these problems, using seafloor spreading data and rotation parameters generated by a mixture of visual fitting of magnetic isochron data and iterative joint inversion of magnetic isochron and fracture zone data. Using plate motion vectors and plate boundary geometries derived from this model, the first-order regional stress pattern was modelled for distinct phases of margin formation. The stress pattern is correlated with the tectono-stratigraphic history of related sedimentary basins. The plate kinematic model identifies three phases of spreading, from the Jurassic to the Paleogene, which resulted in the formation of three main oceanic basins. Prior to these phases, intracontinental 'Karoo' rifting episodes in the late Carboniferous to late Triassic had failed to break up Gondwana, but initiated the formation of sedimentary basins along the East African and West Madagascan margins. At the start of the first phase of spreading (183 to 133 Ma) predominantly NW - SE extension caused continental rifting that separated Madagascar/India/Antarctica from Africa. Maximum horizontal stresses trended perpendicular to the local plate-kinematic vector, and parallel to the rift axes. During and after continental break-up and subsequent spreading, the regional stress regime changed drastically. The extensional stress regime became restricted to the active spreading ridges that in turn adopted trends

  19. Interactions between Eurasian/African and Arabian plates: Eskişehir Fault, NW Turkey

    NASA Astrophysics Data System (ADS)

    Özden, Süha; Gündoğdu, Erdem; Bekler, Tolga

    2015-11-01

    The Eskişehir Fault is an active right-lateral widespread intra-continental deformation zone which separates central western Anatolia from the Aegean domain. The inversion of fault slip vectors along the Eskişehir Fault yields a strike-slip stress state with NW-trending σHmax (σ1) and NE-trending σHmin (σ3) axes since the Early Pliocene. A change in strike-slip faulting under a compressional stress regime: from old transpression to young transtension, probably occurred in the Quaternary. The inversion of the earthquake source mechanism indicates that the transtensional stress regime continues up to the present. The İnönü and Eskişehir Basins developed under the transtensional stress regime producing consistent and local normal faulting with a continuing NE-trending σHmin (σ3). The stress regime change resulted in a decrease in σHmax (σ1) and/or an increase in σHmin (σ3) stress magnitudes due to coeval influence of the superimposed plate forces and the interaction of three plates (Eurasian/African/Arabian): (1) continental collision of Eurasian/Arabian plates with Anatolian block in the east, (2) westward escape of the Anatolian block by anticlockwise rotation at the west-southwest border of the Eurasian and Arabian/African plates and (3) a complex subduction process between African and Eurasian plates along the Aegean (Hellenic) and the Cyprus arcs which favors western extrusion of the Anatolian block in the eastern Mediterranean region.

  20. Seismotectonic features of the African plate: the possible dislocation of a continent

    NASA Astrophysics Data System (ADS)

    Meghraoui, Mustapha

    2014-05-01

    , the Libyan rifting and Maghreb thrusting. Although bearing a relatively slow deformation with regards to the East Africa Rift System, the Nubia plate previously considered as a homogeneous tectonic block appears to be dislocating progressively also forming a system of microplates. A synthesis of earthquake studies and regional deformation exposed in a seismotectonic map hitherto serves as a basis for the seismic hazard evaluations and the reduction of seismic risks. * IGCP/SIDA: International Geoscience Program/Swedish International Cooperation Authority http://www.unesco.org/science/IGCP IGCP-601 Working Group: Paulina Amponsah (Ghana Atomic Energy Commission), Atalay Ayele (Addis Ababa University, Ethiopia), Bekoa Ateba (Inst. of Geol. and Min. Res., Buea, Cameroon), Abdelhakim Ayadi (CRAAG, Algeria), Abdunnur Bensuleman (University of Tripoli, Libya), Damien Delvaux (Royal Museum for Central Africa, Tervuren, Belgium), Mohamed El Gabry (National Research Institute of Geophysics, Cairo, Egypt), Rui-Manuel Fernandes (Universidade da Beira Interior, Portugal), Mustapha Meghraoui (IPG Strasbourg, France), Vunganai Midzi & Magda Roos (Council for Geoscience, Pretoria, South Africa), and Youssef Timoulali (CNRST, Rabat, Morocco).

  1. Seismic Anisotropy beneath the African Plate using Shear Wave Splitting Measurements from AfricaArray Stations

    NASA Astrophysics Data System (ADS)

    Nunley, M. E.; Weeraratne, D.; Nyblade, A.

    2011-12-01

    The African continental plate is made up of a series of cratons and fold belts with activation ages ranging from present to Archean. Recent studies have shown that this tectonic assemblage occurred over a long history of accretion and rifting cycles that likely left behind the complex crust and lithospheric fabric that we see today. Here we study seismic anisotropy beneath the African continent using a large array of permanent AfricaArray and Global Seismic Network seismic stations located throughout Africa. We supply shear wave splitting techniques to teleseismic earthquake events using the eigenvalue method where the second eigenvalue is minimized to determine anisotropy. Stations located in the Ethiopian rift zone yield a NE-SW fast direction with the largest delay times of 1.5s. One station (KOWA) located in the west African craton displays a NW-SE fast direction. Stations located near Cameroon, at the coastal edge of the central African shear zone, produce NW-SE fast directions oriented perpendicular to the shear zone axis. . A group of stations located on Archean crust in central Africa skirt the Congo craton and display consistent NNE fast directions and delay times of 1.0s. Two stations, LSZ and TEZI are located in the Damara suture belt between the Congo and Kaapvaal cratons display a NE-SW fast direction parallel to the suture axis. In the Kaapvaal craton region the average anisotropic direction is NNE with a 1.0s delay time. New stations available south of the Kaapvaal craton reveal a NE fast direction with delay times that vary from 0.5 to 1.3 s. Several splitting measurements are made for the southern station HVD which display backazimuth dependence producing NW-SE fast directions for ray paths coming from the east and are consistent with observations at GRM located east of HVD. These results show that seismic anisotropy across the continent is not uniform and shows significant variation between tectonic regions. While mantle flow and lithospheric

  2. Inherited segmentation of the Iberian-African margins and tectonic reconstruction of a diffuse plate boundary.

    NASA Astrophysics Data System (ADS)

    Fernàndez, Manel; Torne, Montserrat; Vergés, Jaume; Casciello, Emilio

    2016-04-01

    Diffuse plate-boundary regions are characterized by non-well defined contacts between tectonic plates thus making difficult their reconstruction through time. The Western Mediterranean is one of these regions, where the convergence between the African and Iberian plates since Late Cretaceous resulted in the Betic-Rif arcuate orogen, the Gulf of Cadiz imbricate wedge, and the Alboran back-arc basin. Whereas the Iberia-Africa plate boundary is well defined west to the Gorringe Bank and along the Gloria Fault, it becomes much more diffuse eastwards with seismicity spreading over both the south-Iberian and north-African margins. Gravity data, when filtered for short wavelengths, show conspicuous positive Bouguer anomalies associated with the Gorringe Bank, the Gulf of Cadiz High and the Ronda/Beni-Bousera peridotitic massifs reflecting an inherited Jurassic margin segmentation. The subsequent Alpine convergence between Africa and Iberia reactivated these domains, producing crustal-scale thrusting in the Atlantic segments and eventually subduction in the proto-Mediterranean segments. The Jurassic segmentation of the Iberia-Africa margins substantiates the double-polarity subduction model proposed for the region characterized by a change from SE-dipping polarity in the Gorringe, Gulf of Cadiz and Betic-Rif domains, to NW-dipping polarity in the proto-Algerian domain. Therefore, the Algerian and Tyrrhenian basins in the east and the Alboran basin in the west are the result of SSE-E and NW-W retreating slabs of oceanic and/or hyper-extended Tethyan domains, respectively.

  3. Indian and African plate motions driven by the push force of the Réunion plume head.

    PubMed

    Cande, Steven C; Stegman, Dave R

    2011-07-01

    Mantle plumes are thought to play an important part in the Earth's tectonics, yet it has been difficult to isolate the effect that plumes have on plate motions. Here we analyse the plate motions involved in two apparently disparate events--the unusually rapid motion of India between 67 and 52 million years ago and a contemporaneous, transitory slowing of Africa's motion--and show that the events are coupled, with the common element being the position of the Indian and African plates relative to the location of the Réunion plume head. The synchroneity of these events suggests that they were both driven by the force of the Réunion plume head. The recognition of this plume force has substantial tectonic implications: the speed-up and slowdown of India, the possible cessation of convergence between Africa and Eurasia in the Palaeocene epoch and the enigmatic bends of the fracture zones on the Southwest Indian Ridge can all be attributed to the Réunion plume. PMID:21734702

  4. Relative motions between oceanic plates of the Pacific Basin

    NASA Astrophysics Data System (ADS)

    Engebretson, David C.; Cox, Allan; Gordon, Richard G.

    1984-11-01

    Appendix tables are available with entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C., 20009. Document B84-012; $2.50. Payment must accompany order. Relative motion poles describing the displacement histories between the Pacific plate and once adjacent oceanic plates (Farallon, Kula, Izanagi I, Izanagi II, and Phoenix) were derived for the late Mesozoic and Cenozoic eras. Because fracture zone and magnetic anomaly data are generally available from the Pacific plate but not from adjacent plates, a new method of analysis for onesided data was required. This analysis produced stage poles and rates of relative plate motion and estimates of their confidence regions. The following are the main conclusions drawn from our analysis: (1) For time intervals of the order of 107 years, termed stages, relative motion poles for plate pairs remained nearly fixed. Between stages, shifts in poles were commonly both large and abrupt. Within stages, rates of plate motion were commonly observed to change markedly, indicating that plates changed speed more frequently than they changed direction. (2) The relative motions of all of the plates analyzed changed at about chron M11 (135 Ma), chron 34 (85 Ma), and chron 25 (56 Ma). (3) During the Early Cretaceous there were five oceanic plates in the Pacific basin rather than the four recognized by previous workers. (4) To determine the number of Farallon plates that existed to the east of the Pacific plate during the time interval from chron 34 (85 Ma) to chron 25 (56 Ma), fracture zones and magnetic anomalies that record Pacific-Farallon spreading from the northern, central, and southern Pacific plate were analyzed separately and collectively. The analysis shows that a single Pacific-Farallon relative motion pole and a single rate are consistent with all of the data. (5) Spreading rates along the Pacific-Kula ridge decreased markedly between chrons 32b and 25 (72-56 Ma), probably

  5. A wide-angle seismic survey of the Hecataeus Ridge, south of Cyprus: a microcontinental block from the African plate docked in a subduction zone?

    NASA Astrophysics Data System (ADS)

    Rahimi, Ayda; Welford, Kim; Hall, Jeremy; Hübscher, Christian; Louden, Keith; Ehrhardt, Axel

    2013-04-01

    Cyprus lies at the southern edge of the Aegean-Anatolian microplate, caught in the convergence of Africa and Eurasia. Subduction of the African plate below Cyprus has probably ceased and this has been attributed to the docking in the subduction zone of the Eratosthenes Seamount microcontinental fragment on the northern edge of the African plate. In early 2010, on R.V. Maria S. Merian, we conducted a wide-angle seismic survey to test the hypothesis that the Hecataeus Ridge, another possible microcontinental block lying immediately offshore SE Cyprus, might be related to an earlier docking event. The upper crust of southern Cyprus is dominated by ophiolites, with seismic velocities of up to 7 km s-1. A wide angle seismic profile along Hecataeus Ridge was populated with 15 Canadian and German ocean-bottom seismographs at 5 km intervals and these recorded shots from a 6000 cu. in. air gun array, fired approximately every 100 m. Rough topography of the seabed has made picking of phases and their modelling a demanding task. Bandpass and coherency filtering have enabled us to pick phases out to around 80 km. Tomographic inversion of short-range first arrivals provided an initial model of the shallow sub-seabed structure. Forward modelling by ray-tracing, using the code of Zelt and Smith, was then used to model crustal structure down to depths of around 20 km, with occasional evidence of reflections from deeper boundaries (Moho?). Modelling results provide good control on P-wave velocities in the top 20 km and some indications of deeper events. There is no evidence of true velocities approaching 7 km/s in the top 20 km below the Ridge that might indicate the presence of ophiolitic rocks. Regional gravity and magnetic field data tend to support this proposition. We thus conclude that Hecataeus Ridge is not composed of characteristically ophiolitic, Cyprus (upper plate) crust, and it might well be derived from the African (lower) plate.

  6. Development of transtensional and transpressive plate boundaries due to noncircular (cycloid) relative plate motion

    SciTech Connect

    Cronin, V.S. )

    1990-05-01

    The trace of a transform fault commonly is assumed to be circular and concentric with the finite relative motion of the plates adjacent to the fault. These assumptions have led to controversy as the transform fault label has been applied to the San Andreas fault in California because the San Andreas fault is neither circular nor concentric with the motion of the Pacific plate relative to the North American plate. The assumption of circular relative plate motion over a finite time interval is not generally valid. When finite relative plate motion is not circular, the length and orientation of a transform fault must change through time. The length and orientation of ridge-ridge transform faults in oceanic crust evolve through the migration, propagation, and abandonment of ridge segments. Transform faults that bound continental crust evolve differently than do transform faults along mid-ocean ridges because continental transform faults typically do not have ridges at both ends and because of the rheological differences between oceanic and continental crust. Along continent-continent transform faults in which the initial displacement is entirely strike slip, later displacements will be progressively more divergent or convergent (i.e., transtensive or transpressive). Transtension can result in the development of deep basins with high heat flow. Transpression can result in folding, reverse faulting, and decoupling of the crust from its lower crustal or mantle lithosphere in the region adjacent to the transform fault. Regardless of whether the transform boundary becomes transtensional or transpressional, the boundary evolves from a discrete transform fault to a broader, structurally complex accommodation zone (sensu lato).

  7. Is Nubia plate rigid? A geodetic study of the relative motion of different cratonic areas within Africa.

    NASA Astrophysics Data System (ADS)

    Njoroge, M. W.; Malservisi, R.; Hugentobler, U.; Mokhtari, M.; Voytenko, D.

    2014-12-01

    Plate rigidity is one of the main paradigms of plate tectonics and a fundamental assumption in the definition of a global reference frame as ITRF. Although still far for optimal, the increased GPS instrumentation of the African region can allow us to understand how rigid one of the major plate can be. The presence of diffused band of seismicity, the Cameroon volcanic line, Pan African Kalahari orogenic belt and East Africa Rift suggest the possibility of relative motion among the different regions within the Nubia. The study focuses on the rigidity of Nubia plate. We divide the plate into three regions: Western (West Africa craton plus Nigeria), Central (approximately the region of the Congo craton) and Southern (Kalahari craton plus South Africa) and we utilize Euler Vector formulation to study internal rigidity and eventual relative motion. Developing five different reference frames with different combinations of the 3 regions, we try to understand the presence of the relative motion between the 3 cratons thus the stability of the Nubia plate as a whole. All available GPS stations from the regions are used separately or combined in creation of the reference frames. We utilize continuous stations with at least 2.5 years of data between 1994 and 2014. Given the small relative velocity, it is important to eliminate eventual biases in the analysis and to have a good estimation in the uncertainties of the observed velocities. For this reason we perform our analysis using both Bernese and Gipsy-oasis codes to generate time series for each station. Velocities and relative uncertainties are analyzed using the Allan variance of rate technique, taking in account for colored noise. An analysis of the color of the noise as function of latitude and climatic region is also performed to each time series. Preliminary results indicate a slight counter clockwise motion of West Africa craton with respect to South Africa Kalahari, and South Africa Kalahari-Congo Cratons. In addition

  8. The San Andreas fault experiment. [gross tectonic plates relative velocity

    NASA Technical Reports Server (NTRS)

    Smith, D. E.; Vonbun, F. O.

    1973-01-01

    A plan was developed during 1971 to determine gross tectonic plate motions along the San Andreas Fault System in California. Knowledge of the gross motion along the total fault system is an essential component in the construction of realistic deformation models of fault regions. Such mathematical models will be used in the future for studies which will eventually lead to prediction of major earthquakes. The main purpose of the experiment described is the determination of the relative velocity of the North American and the Pacific Plates. This motion being so extremely small, cannot be measured directly but can be deduced from distance measurements between points on opposite sites of the plate boundary taken over a number of years.

  9. Understanding lithospheric stresses: systematic analysis of controlling mechanisms with applications to the African Plate

    NASA Astrophysics Data System (ADS)

    Medvedev, Sergei

    2016-06-01

    Many mechanisms control the state of stress within Earth plates. First-order well-known mechanisms include stresses induced by lateral variations of lithospheric density structure, sublithospheric tractions, ridge push, and subduction pull. In this study, we attempt to quantify the influence of these mechanisms to understand the origin of stresses in the lithosphere, choosing the African plate (TAP) as an example. A finite-element based suite, Proshell, was developed to combine several data sets, to estimate the gravitational potential energy (GPE) of the lithosphere, and to calculate stresses acting on the real (non-planar) geometry of TAP. We introduce several quantitative parameters to measure the degree of fit between the model and observations. Our modelling strategy involves nine series of numerical experiments. We start with the simplest possible model and then, step by step, build it up to be a more physically realistic model, all the while discussing the influence of each additional component. The starting (oversimplified) model series (1) is based on the CRUST2 data set for the crust, and a half-space-cooling approximation of the lithospheric mantle. We then describe models (series 2-5) that account for lithospheric mantle density heterogeneities to build a more reliable GPE model. The consecutive series involve basal traction from the convective mantle (series A, C), and the rheological heterogeneity of the TAP via variations in its effective elastic thickness (series B, C). The model quality reflects the increase in complexity between series with an improving match toobserved stress regimes and directions. The most complex model (series D) also accounts for the bending stresses in the elastic lithosphere and achieves a remarkably good fit to observations. All of our experiments were based on the iteration of controlling parameters in order to achieve the best fit between modelled and observed stresses, always considering physically feasible values. This

  10. Gender as a Moderator of the Relation between Race-Related Stress and Mental Health Symptoms for African Americans

    ERIC Educational Resources Information Center

    Greer, Tawanda M.; Laseter, Adrian; Asiamah, David

    2009-01-01

    The present study tested gender as a moderator of the relationship between race-related stress and mental health symptoms among African American adults. Because African American women are exposed to stressors associated with race and gender, we hypothesized that African American women would have higher levels of race-related stress and more severe…

  11. 77 FR 20846 - Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... COMMISSION Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof... importation of certain food containers, cups, plates, cutlery, and related items and packaging thereof by... importation of certain food containers, cups, plates, cutlery, and related items and packaging thereof...

  12. Euler Pole Determination of the Philippine Sea Plate Relative to the Caroline Plate from Bathymetric Information Collected at Ayu Trough

    NASA Astrophysics Data System (ADS)

    Choi, H.; Lee, S.

    2010-12-01

    The reconstruction of past positions of continents and oceans is one of the main goals of global tectonic investigations. The relative motion of rigid plate on a sphere can be described in terms of Euler pole, which is normally determined by comparing two pairing sets of magnetic anomalies across divergent boundary. However, in some cases, magnetic anomalies are so subdued that the comparison is practically impossible. The Ayu Trough represents such a case. It is a slow, east-west-spreading mid-ocean ridge that lies between the Caroline and the Philippine Sea plates, but due to its location near the magnetic equator, the exact motion of the two plates cannot be resolved by traditional means of by matching magnetic anomalies at two plates. In this study, we use seafloor topography that was obtained from high-resolution multi-beam bathymetric survey performed earlier to reconstruct the plate motions across the Ayu Trough. Our approach is similar to that outlined by T. Chang (1988) and others over the years but comparing detailed bathymetric information across two plates instead of magnetic anomalies. The comparison of bathymetry not only provided the best fitting Euler pole between Philippine Sea plate and Caroline plate presumably going back to 25 Ma but also the uncertainty associated with this estimate.

  13. The Rift Valley of African Plate in Elasto-Plastic Creeping over Magma Motion

    NASA Astrophysics Data System (ADS)

    Nakamura, Shigehisa

    2016-04-01

    This is a brief note to a problem on the Rift Valley in the eastern Africa. It is said that this valley was formed in an age 20,000,000 years before present though the valley is yet continuing to move eastward at an annual rate of about 5 cm/year in a geographical trend. Adding to some of the scientists tell that the separation threat of the easternAfrica from the mother land of the Africa under the effect of African crust motion over the magma. However, it is now geological understanding that the land of the Africa has been kept its basic coastal configulation in geographic pattern since the time more than 20,000,000 years before present. Sothat, it is hard to consider the above noted African land separation by part could be in the next age in a time scale of 20,000,000 years. As far as, we concern the geographic data obtaoned by the ground based survey of the African typical mountain peaks, the highest mountain peak 5885m (in 1980) is for Kilimanjaro, Kibo Peak though one of the scientific almanacs tells us its peak height as 5890m (in 2009). As for the Mount Kenia, the peak height is as 5199m (in 1980) and 5200m(in 2009). At a glance, it looks to be a trend in altimetry of the African typical mountain. Now, what trends are noted for the peak heights could be taken to suggesting the geological activity on the earth surface to maintain in a spherical shape approximately on the orbit around the Sun. In these several ten years, the digitizing of the data has been promoted even for the topographic patterns on the earth though its time scaling is extremely short comparing to the geological time scaling. Now, it should be found what is effective to monitor any trends of the African crust in motion as well as variations of the mountain peaks.

  14. Work Socialization and Adolescents' Work-Related Values in Single-Mother African American Families

    ERIC Educational Resources Information Center

    Toyokawa, Teru; McLoyd, Vonnie C.

    2013-01-01

    This study examined African American mothers' work socialization messages in relation to adolescents' work-related values. Moderation effects of mother-adolescent relation quality on the linkage between maternal socialization messages and adolescents' outcomes were also examined. Participants were 245 single African American mothers and their…

  15. UHPLC/HRMS Analysis of African Mango (Irvingia gabonensis) Seeds, Extract and Related Dietary Supplements

    PubMed Central

    Sun, Jianghao; Chen, Pei

    2012-01-01

    Dietary Supplements based on an extract from Irvingia gabonensis (African Mango, AM for abbreviation) seeds are one of the popular herbal weight loss dietary supplements in the US market. The extract is believed to be a natural and healthy way to lose weight and improve overall health. However, the chemical composition of African mango based-dietary supplements (AMDS) has never been reported. In this study, the chemical constituents of African mango seeds, African mango seeds extract (AMSE), and different kinds of commercially available African mango based dietary supplements (AMDS) have been investigated using an ultra high-performance liquid chromatography with high resolution mass spectrometry (UHPLC-HRMS) method. Ellagic acid, mono, di, tri-O methyl-ellagic acids and their glycosides were found as major components in African Mango seeds. These compounds may be used for quality control of African Mango extract and related dietary supplements. PMID:22880691

  16. An Investigation of African American Parents' Perception of School Leaders as It Relates to Parent Engagement and the African American Male Student

    ERIC Educational Resources Information Center

    Currie, Delvon Denise

    2013-01-01

    The purpose of this study was to investigate African American parents' perception of school leaders as it relates to parent engagement and the African American male student. Specifically, this study addressed African American parents' perceptions of the quality of their child's education and the quality of communication they received from their…

  17. Coping with HIV-related stigma in five African countries.

    PubMed

    Makoae, Lucia N; Greeff, Minrie; Phetlhu, René D; Uys, Leana R; Naidoo, Joanne R; Kohi, Thecla W; Dlamini, Priscilla S; Chirwa, Maureen L; Holzemer, William L

    2008-01-01

    People living with HIV (PLWH) and their families are subjected to prejudice, discrimination, and hostility related to the stigmatization of AIDS. This report examines how PLWH cope with HIV-related stigma in the five southern African countries of Lesotho, Malawi, South Africa, Swaziland, and Tanzania. A descriptive qualitative research design was used to explore the experience of HIV-related stigma of PLWH and nurses in 2004. A total of 43 focus groups were conducted with 251 participants (114 nurses, 111 PLWH, and 26 volunteers). In describing incidents of stigma, respondents reported strategies used or observed to cope with those incidents. Nurse reports of coping strategies that they used as well as observed in HIV-infected patients were coded. Coping strategies used by PLWH in dealing with HIV-related stigma were coded. A total of 17 different self-care strategies were identified: restructuring, seeing oneself as OK, letting go, turning to God, hoping, changing behavior, keeping oneself active, using humor, joining a support or social group, disclosing one's HIV status, speaking to others with same problem, getting counseling, helping others to cope with the illness, educating others, learning from others, acquiring knowledge and understanding about the disease, and getting help from others. Coping appears to be self-taught and only modestly helpful in managing perceived stigma. PMID:18328964

  18. Stalling Out: The Relative Progress of African Americans.

    ERIC Educational Resources Information Center

    Tidwell, Billy J.

    The socioeconomic progress of African Americans appears to be in a stalled state. This study analyzes the progress of African Americans toward parity with Whites over a 15- to 20-year period in the following areas: (1) employment; (2) economic development; (3) education; (4) health; (5) housing; and (6) political empowerment. For individual…

  19. West African warming: Investigating Temperature Trends and their relation between Precipitation Trends over West African Sahel.

    NASA Astrophysics Data System (ADS)

    LY, M., Jr.

    2014-12-01

    It is now admitted that the West African region faces a lot of constraints due to the comprehensiveness of the high climate variability and potential climate change. This is mainly due to the lack of a large number of datasets and long-term records as summarized in the in the IPCC reports. This paper aims to provide improved knowledge and evidence on current and future climate conditions, for better manage climate variability over seasons and from year to year and strengthen the capacity to adapt to future climate change. In this regards, we analyse the evolution of some extreme temperature and precipitation indices over a large area of West Africa. Prior results show a general warming trend at individual stations throughout the region during the period from 1960 to 2010, namely negative trends in the number of cool nights, and positive trends in the number of warm days and length of warm spells. Trends in rainfall-related indices are not as uniform as the ones in temperatures, rather they display marked multi-decadal variability, as expected. To refine analyses of temperature variations and their relation to precipitation we investigated on cluster analysis aimed at distinguishing different sub-regions, such as continental and coastal, and relevant seasons, such as wet, dry/cold and dry warm. This will contribute to significantly lower uncertainties by developing better and more tailored temperature and precipitation trends to inform the user communities on climate related risks, as well as enhance their resilience to food insecurity and other climate related disasters.

  20. The African Renaissance and its relation to the geosciences: a South African perspective

    NASA Astrophysics Data System (ADS)

    Mtimkulu, M. N.; Motloung, M.; Graham, I. T.; Eriksson, P. G.; Bumby, A. J.

    2001-08-01

    Implicit in the African Renaissance is the synergy between government, the private sector, the educated minority and the disadvantaged majority. For this concept to work, belief and commitment must arise first from the African individual, whatever his or her potential contribution may be. The geosciences in South Africa provide a currently vibrant example of such cooperation, which has the potential to contribute significantly to the upliftment of the country and its neighbouring states. Based largely on personal interviews with various role players, from the Presidency of South Africa, through ministerial levels, the corporate sector and down to the individual, we present a spectrum of viewpoints and initiatives which are starting to result in practical implementation of the African revival. An end to conflict and xenophobia, the entrenchment of democratic government and corporate expression of the entrepreneurial spirit are essential to provide the framework within which the individual African can become a "Renaissance Man or Woman".

  1. African ancestry protects against Alzheimer's disease-related neuropathology

    PubMed Central

    Schlesinger, D; Grinberg, L T; Alba, J G; Naslavsky, M S; Licinio, L; Farfel, J M; Suemoto, C K; de Lucena Ferretti, R E; Leite, R E P; de Andrade, M P; dos Santos, A C F; Brentani, H; Pasqualucci, C A; Nitrini, R; Jacob-Filho, W; Zatz, M

    2013-01-01

    Previous studies in dementia epidemiology have reported higher Alzheimer's disease rates in African-Americans when compared with White Americans. To determine whether genetically determined African ancestry is associated with neuropathological changes commonly associated with dementia, we analyzed a population-based brain bank in the highly admixed city of São Paulo, Brazil. African ancestry was estimated through the use of previously described ancestry-informative markers. Risk of presence of neuritic plaques, neurofibrillary tangles, small vessel disease, brain infarcts and Lewy bodies in subjects with significant African ancestry versus those without was determined. Results were adjusted for multiple environmental risk factors, demographic variables and apolipoprotein E genotype. African ancestry was inversely correlated with neuritic plaques (P=0.03). Subjects with significant African ancestry (n=112, 55.4%) showed lower prevalence of neuritic plaques in the univariate analysis (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.55–0.95, P=0.01) and when adjusted for age, sex, APOE genotype and environmental risk factors (OR 0.43, 95% CI 0.21–0.89, P=0.02). There were no significant differences for the presence of other neuropathological alterations. We show for the first time, using genetically determined ancestry, that African ancestry may be highly protective of Alzheimer's disease neuropathology, functioning through either genetic variants or unknown environmental factors. Epidemiological studies correlating African-American race/ethnicity with increased Alzheimer's disease rates should not be interpreted as surrogates of genetic ancestry or considered to represent African-derived populations from the developing nations such as Brazil. PMID:22064377

  2. Multiple Myeloma Mortality in Relation to Obesity Among African Americans.

    PubMed

    Sonderman, Jennifer S; Bethea, Traci N; Kitahara, Cari M; Patel, Alpa V; Harvey, Chinonye; Knutsen, Synnøve F; Park, Yikyung; Park, Song-Yi; Fraser, Gary E; Teras, Lauren R; Purdue, Mark P; Stolzenberg-Solomon, Rachael Z; Gillanders, Elizabeth M; Palmer, Julie R; Kolonel, Laurence N; Blot, William J

    2016-10-01

    Multiple myeloma (MM) incidence and mortality are higher among African Americans (AAs) than among other population groups. The prevalence of obesity is also elevated among AAs, but few studies have examined risk of this cancer in relation to body size among AAs. We combined data from seven prospective cohorts tracking mortality among 239 597 AA adults and used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for death because of MM according to body mass index (BMI) at cohort entry, adjusted for age (as time-scale) and sex. Relative to those with normal BMIs (18.5-25 kg/m(2)), mortality increased monotonically as BMI increased, with hazard ratios reaching 1.43 (95% CI = 1.03 to 1.97) for BMIs of 35 kg/m(2) or greater. The findings suggest that obesity is a risk factor for MM and a contributor to the elevated rates and rising incidence trends of MM among AAs in the United States. PMID:27147231

  3. Relative motions of the Australian, Pacific and Antarctic plates estimated by the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Larson, Kristine M.; Freymueller, Jeff

    1995-01-01

    Global Positioning System (GPS) measurements spanning approximately 3 years have been used to determine velocities for 7 sites on the Australian, Pacific and Antarctic plates. The site velocities agree with both plate model predictions and other space geodetic techniques. We find no evidence for internal deformation of the interior of the Australian plate. Wellington, New Zealand, located in the Australian-Pacific plate boundary zone, moves 20 +/- 5 mm/yr west-southwest relative to the Australian plate. Its velocity lies midway between the predicted velocities of the two plates. Relative Euler vectors for the Australia-Antarctica and Pacific-Antarctica plates agree within one standard deviation with the NUVEL-1A predictions.

  4. 77 FR 14423 - Certain Food Containers, Cups, Plates, Cutlery, and Related Items, and Packaging Thereof; Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... COMMISSION Certain Food Containers, Cups, Plates, Cutlery, and Related Items, and Packaging Thereof; Notice... Related Items, and Packaging Thereof, DN 2883; the Commission is soliciting comments on any public... containers, cups, plates, cutlery, and related items, and packaging thereof. The complaint names...

  5. Individual and Social Factors Related to Urban African American Adolescents' School Performance

    ERIC Educational Resources Information Center

    Somers, Cheryl L.; Owens, Delila; Piliawsky, Monte

    2008-01-01

    The purpose of this study was to examine factors related to the academic success of urban, African American youth. Participants were 118 African American male and female ninth graders from a large urban high school in the Midwest. A majority of students at the school receive free or reduced lunch. Factors studied were social support from five…

  6. Sisters in the Struggle: African American Female Graduate Students Coping with Racism and Racism-Related

    ERIC Educational Resources Information Center

    Foster, Kelsie

    2013-01-01

    This study examined if coping was predictive of perceived racism and racism related stress of African American female graduate students. Participants were 217 African American female graduate students attending Predominantly White Institutions (PWIs), Hispanic Serving Institutions (HSIs) and Historically Black Colleges and Universities (HBCUs) and…

  7. Understanding African American Adolescents' Identity Development: A Relational Developmental Systems Perspective

    ERIC Educational Resources Information Center

    Brittian, Aerika S.

    2012-01-01

    This article examines the development of African American adolescents' identity using a relational developmental systems theory framework, which led to the expectation that identity development is linked to both the reduction of risk behaviors and the promotion of African American adolescents' healthy development. Different personological theories…

  8. Helminth-related Eosinophilia in African Immigrants, Gran Canaria

    PubMed Central

    Pardo, Javier; Carranza, Cristina; Muro, Antonio; Angel-Moreno, Alfonso; Martín, Antonio-Manuel; Martín, Teresa; Hernández-Cabrera, Michele

    2006-01-01

    Of 788 recent African adult immigrants to Las Palmas de Gran Canaria, 213 (27.0%) had eosinophilia. The most frequent causes were filariasis (29.4%), schistosomiasis (17.2%), and hookworm infection (16.8%). Stool microscopy and filarial and schistosomal serologic tests gave the highest diagnostic yield. Country of origin and eosinophil count were associated with specific diagnoses. PMID:17176579

  9. RELATIONAL SCHEMAS, HOSTILE ROMANTIC RELATIONSHIPS, AND BELIEFS ABOUT MARRIAGE AMONG YOUNG AFRICAN AMERICAN ADULTS

    PubMed Central

    Simons, Ronald L.; Simons, Leslie Gordon; Lei, Man Kit; Landor, Antoinette

    2011-01-01

    The present study tests a developmental model designed to explain the romantic relationship difficulties and reluctance to marry often reported for African Americans. Using longitudinal data from a sample of approximately 400 African American young adults, we examine the manner in which race-related adverse experiences during late childhood and early adolescence give rise to the cynical view of romantic partners and marriage held by many young African Americans. Our results indicate that adverse circumstances disproportionately suffered by African American youth (viz., harsh parenting, family instability, discrimination, criminal victimization, and financial hardship) promote distrustful relational schemas that lead to troubled dating relationships, and that these negative relationship experiences, in turn, encourage a less positive view of marriage. PMID:22328799

  10. Less Drinking, Yet More Problems: Understanding African American Drinking and Related Problems

    PubMed Central

    Zapolski, Tamika C. B.; Pedersen, Sarah L.; McCarthy, Denis M.; Smith, Gregory T.

    2013-01-01

    Researchers have found that, compared to European Americans, African Americans report later initiation of drinking, lower rates of use, and lower levels of use across almost all age groups. Nevertheless, African Americans also have higher levels of alcohol problems than European Americans. After reviewing current data regarding these trends, we provide a theory to understand this apparent paradox as well as to understand variability in risk among African Americans. Certain factors appear to operate as both protective factors against heavy use and risk factors for negative consequences from use. For example, African American culture is characterized by norms against heavy alcohol use or intoxication, which protects against heavy use but which also provides within group social disapproval when use does occur. African Americans are more likely to encounter legal problems from drinking than European Americans, even at the same levels of consumption, perhaps thus resulting in reduced consumption but more problems from consumption. There appears to be one particular group of African Americans, low-income African American men, who are at the highest risk for alcoholism and related problems. We theorize that this effect is due to the complex interaction of residential discrimination, racism, age of drinking, and lack of available standard life reinforcers (e.g., stable employment and financial stability). Further empirical research will be needed to test our theories and otherwise move this important field forward. A focus on within group variation in drinking patterns and problems is necessary. We suggest several new avenues of inquiry. PMID:23477449

  11. Less drinking, yet more problems: understanding African American drinking and related problems.

    PubMed

    Zapolski, Tamika C B; Pedersen, Sarah L; McCarthy, Denis M; Smith, Gregory T

    2014-01-01

    Researchers have found that, compared to European Americans, African Americans report later initiation of drinking, lower rates of use, and lower levels of use across almost all age groups. Nevertheless, African Americans also have higher levels of alcohol problems than European Americans. After reviewing current data regarding these trends, we provide a theory to understand this apparent paradox as well as to understand variability in risk among African Americans. Certain factors appear to operate as both protective factors against heavy use and risk factors for negative consequences from use. For example, African American culture is characterized by norms against heavy alcohol use or intoxication, which protects against heavy use but also provides within-group social disapproval when use does occur. African Americans are more likely to encounter legal problems from drinking than European Americans, even at the same levels of consumption, perhaps thus resulting in reduced consumption but more problems from consumption. There appears to be one particular group of African Americans, low-income African American men, who are at the highest risk for alcoholism and related problems. We theorize that this effect is due to the complex interaction of residential discrimination, racism, age of drinking, and lack of available standard life reinforcers (e.g., stable employment and financial stability). Further empirical research will be needed to test our theories and otherwise move this important field forward. A focus on within-group variation in drinking patterns and problems is necessary. We suggest several new avenues of inquiry. PMID:23477449

  12. The effect of mantle plume heads on the motion between the African and Antarctic plates in the Late Cretaceous and Early Cenozoic

    NASA Astrophysics Data System (ADS)

    Cande, S. C.; Patriat, P.

    2012-12-01

    the fracture zones (and shift in the Africa-Antarctic stage pole) around Chron 24 (53 Ma). Although both India and Africa appear to respond to the Reunion plume head around 71 Ma, it is notable that the time of India's most rapid speedup (starting around Chron 31, at 68 Ma) appears to lag the time of Africa's most rapid slowdown (Chron 32) by two or three million years, a relationship which may be an important clue as to how the Reunion plume head affects the motions of India and Africa. The sudden change in spreading direction between Africa and Antarctica as recorded on the SWIR at Chron 24 (53 Ma) is also puzzling. This change in motion is roughly synchronous with major tectonic events throughout the Atlantic region, which suggests that it was caused by the arrival of the Iceland plume head, whose onset is related to the rifting of Norway and Greenland just before Chron 24. The major Eocene slowing of India and speedup of Africa start soon after this event, around 52 Ma, suggesting that this phase of the coupled motion may also have been triggered by the arrival of the Iceland plume head. Cande, S.C. and D. R. Stegman. Indian and African plate motions driven by the push force of the Reunion plume head, Nature, v. 475, 47-52, 2011.

  13. HIV-related stigma among African-American youth in the Northeast and Southeast US.

    PubMed

    Kerr, Jelani C; Valois, Robert F; Diclemente, Ralph J; Fletcher, Faith; Carey, Michael P; Romer, Daniel; Vanable, Peter A; Farber, Naomi

    2014-06-01

    HIV-related stigma inhibits optimal HIV prevention and treatment among African-Americans. Regional differences in HIV/AIDS prevalence may be related to stigma among young African-Americans. Baseline data (N = 1,606) from an HIV prevention intervention were used to investigate regional differences in HIV-related stigma and knowledge among African-American adolescents in four midsized cities in the Northeastern and Southeastern US. Analyses indicated greater HIV-related stigma among adolescents from the Southeast relative to adolescents from the Northeast (F = 22.23; p < 0.0001). Linear regression indicated a negative relationship between HIV stigma and HIV knowledge (b = -0.65; p < 0.0001). Addressing HIV/AIDS in high prevalence locales should include efforts to reduce HIV-related stigma. PMID:24402690

  14. The Relation of Ethnic Identity, Racial Identity, and Race-Related Stress among African American College Students

    ERIC Educational Resources Information Center

    Johnson, Samon C.; Arbona, Consuelo

    2006-01-01

    The purpose of this study was to explore to what extent ethnic identity and racial identity are related constructs among African American college students by examining (a) the association of racial identity to ethnic identity and (b) the relative and unique contribution of both constructs to race-related stress. Participants were 140 college…

  15. Sociocultural Influences on Weight-Related Behaviors in African American Adolescents.

    PubMed

    Tate, Nutrena H; Davis, Jean E; Yarandi, Hossein N

    2015-12-01

    The purpose of this study was to examine the sociocultural factors related to weight behaviors in African American adolescents utilizing a social ecological approach. A descriptive correlational design included a sample of 145 African American adolescents. Perceived familial socialization, ethnic identity, physical activity, and eating behavior patterns were measured. Data were analyzed using descriptive statistics, Pearson product-moment correlations, and multiple regression equations. Perceived maternal socialization was significantly related to adolescent eating behaviors and physical activity whereas perceived paternal socialization was significantly related only to their physical activity. The adolescents' ethnic identity was not significantly related to their eating behaviors or physical activity. Health care providers who work with adolescents and their families can use the initial findings from this study to encourage healthy weight-related behaviors while reducing the obesity epidemic within the African American adolescent population in a developmentally appropriate and culturally sensitive manner. PMID:24895047

  16. Understanding African American Adolescents’ Identity Development: A Relational Developmental Systems Perspective

    PubMed Central

    Brittian, Aerika S.

    2012-01-01

    This article examines the development of African American adolescents’ identity using a relational developmental systems theory framework, which led to the expectation that identity development is linked to both the reduction of risk behaviors and the promotion of African American adolescents’ healthy development. Different personological theories of identity development were discussed, including Erikson’s theory of psychosocial development and Marcia’s theory of identity statuses. Developmental systems theory was used to further the literature on African American adolescents’ identity development, by integrating various views of identity development as they pertain to these youth. Furthermore, the formation of many aspects of identity may be an important coping and resilience process for such youth. In addition, directions for future research are discussed, including a consideration of the complexity of diversity that exists within the African American adolescent population, and a call for more longitudinal assessments of identity development is presented. PMID:23243325

  17. Medical mistrust is related to lower longitudinal medication adherence among African-American males with HIV.

    PubMed

    Dale, Sannisha K; Bogart, Laura M; Wagner, Glenn J; Galvan, Frank H; Klein, David J

    2016-07-01

    African-Americans living with HIV show worse health behaviors (e.g. medication adherence) and outcomes (e.g. viral suppression) than do their White counterparts. In a 6-month longitudinal study, we investigated whether medical mistrust among African-American males with HIV (214 enrolled, 140 with longitudinal data) predicted lower electronically monitored antiretroviral medication adherence. General medical mistrust (e.g. suspicion toward providers), but not racism-related mistrust (e.g. belief that providers treat African-Americans poorly due to race), predicted lower continuous medication adherence over time (b = -.08, standard error = .04, p = .03). Medical mistrust may contribute to poor health outcomes. Intervention efforts that address mistrust may improve adherence among African-Americans with HIV. PMID:25293970

  18. Relational Variables and Life Satisfaction in African American and Asian American College Women

    ERIC Educational Resources Information Center

    Berkel, LaVerne A.; Constantine, Madonna G.

    2005-01-01

    The authors explored associations among relationship harmony, perceived family conflicts, relational self-concept, and life satisfaction in a sample of 169 African American and Asian American college women. As hypothesized, higher relational self-concept, or the extent to which individuals include close relationships in their self-concepts, and…

  19. Smoking Abstinence-related Expectancies among American Indians, African Americans, and Women: Potential Mechanisms of Tobacco-related Disparities

    PubMed Central

    Hendricks, Peter S.; Westmaas, J. Lee; Park, Van M. Ta; Thorne, Christopher B.; Wood, Sabrina B.; Baker, Majel R.; Lawler, R. Marsh; Hooper, Monica Webb; Delucchi, Kevin L.; Hall, Sharon M.

    2014-01-01

    Research has documented tobacco-related health disparities by race and gender. Prior research, however, has not examined expectancies about the smoking cessation process (i.e., abstinence-related expectancies) as potential contributors to tobacco-related disparities in special populations. This cross-sectional study compared abstinence-related expectancies between American Indian (n = 87), African American (n = 151), and White (n = 185) smokers, and between women (n = 231) and men (n = 270) smokers. Abstinence-related expectancies also were examined as mediators of race and gender relationships with motivation to quit and abstinence self-efficacy. Results indicated that American Indians and African Americans were less likely than Whites to expect withdrawal effects, and more likely to expect that quitting would be unproblematic. African Americans also were less likely than Whites to expect smoking cessation interventions to be effective. Compared to men, women were more likely to expect withdrawal effects and weight gain.These expectancy differences mediated race and gender relationships with motivation to quit and abstinence self-efficacy. Findings emphasize potential mechanisms underlying tobacco-related health disparities among American Indians, African Americans, and women, and suggest a number of specific approaches for targeting tobacco dependence interventions to these populations. PMID:23528192

  20. Characterizing the learning styles and testing the science-related attitudes of African American middle school students: Implications for the underrepresentation of African Americans in the sciences

    NASA Astrophysics Data System (ADS)

    Perine, Donald Ray

    African Americans, Hispanics, Native Americans and women are underrepresented among the population of scientists and science teachers in the United States. Specifically, the shortage of African Americans teaching math and science at all levels of the educational process and going into the many science-related fields is manifested throughout the entire educational and career structure of our society. This shortage exists when compared to the total population of African Americans in this country, the population of African American students, and to society's demand for more math and science teachers and professionals of all races. One suggestion to address this problem is to update curricular and instructional programs to accommodate the learning styles of African Americans from elementary to graduate school. There is little in the published literature to help us understand the learning styles of African American middle school students and how they compare to African American adults who pursue science careers. There is also little published data to help inform us about the relationship between learning styles of African American middle school students and their attitudes toward science. The author used a learning styles inventory instrument to identify the learning style preferences of the African American students and adults. The preferences identified describe how African American students and African American adult science professionals prefer to function, learn, concentrate, and perform in their educational and work activities in the areas of: (a) immediate environment, (b) emotionality, (c) sociological needs, and (d) physical needs. The learning style preferences for the students and adults were not significantly different in key areas of preference. A Test of Science-Related Attitudes (TOSRA) was used to measure seven distinct science-related attitudes of the middle school students. A comparison of the profile of the mean scores for the students in this study

  1. Reading ability and computer-related attitudes among African American graduate students.

    PubMed

    Collins, Kathleen M T; Onwuegbuzie, Anthony J; Jiao, Qun G

    2008-06-01

    This study examined the degree that African American graduate students' reading abilities predict their attitudes toward computers and the educational use of the Internet. A canonical correlation analysis revealed that students with the lowest levels of reading ability tended to report the least computer confidence, least positive attitudes regarding computer liking, and least positive attitudes toward the educational use of the Internet. Findings of the study provide support for the hypothesis that reading ability differentially impacts African American graduate students' computer-related attitudes. The findings also suggest that reading ability may impede African American students' acquisition of computer and Internet skills and may negatively impact their achievement levels in graduate courses requiring computer-based skills. PMID:18537506

  2. African American Career Aspirations: Examining the Relative Influence of Internalized Racism

    ERIC Educational Resources Information Center

    Brown, Danice L.; Segrist, Daniel

    2016-01-01

    The present study examined the relative influence of aspects of internalized racism on the career aspirations of a sample of African American adults. Participants (N = 315), ranging in age from 18 to 62 years, completed measures of internalized racism and career aspirations online. A hierarchical multiple regression analysis was conducted to…

  3. African American College Students' Health Behaviors and Perceptions of Related Health Issues.

    ERIC Educational Resources Information Center

    Ford, Denyce S.; Goode, Carolyn R.

    1994-01-01

    A study of African American college students compared students' health-related behaviors with their perceptions of corresponding health issues. Students had low smoking rates but higher alcohol consumption. Most students did not practice good nutrition or daily physical activity. Over half managed stress well, and three-quarters were sexually…

  4. Emotion-Related Behavioral Regulation in African American Preschoolers: Social-Emotional Correlates of Teacher Perceptions

    ERIC Educational Resources Information Center

    Smith, Maureen C.

    2004-01-01

    This preliminary and exploratory study examined the correlates of 5 aspects of teacher-rated emotion-related regulation (modulation, flexibility, organization, emotion-focused coping, aggressive-coping strategies) in a sample of 36 low- to middle-income African American preschoolers. Results showed that children's empathy, emotional intensity,…

  5. Ring of Silence: African American Women's Experiences Related to Their Breasts and Breast Cancer Screening

    ERIC Educational Resources Information Center

    Thomas, Eileen

    2006-01-01

    The purpose of this study was to explore women's memories and feelings concerning their breasts and breast cancer screening experiences in relation to their current breast cancer screening behaviors. Twelve African American women shared stories that were generated in written narratives and individual interviews. Two core themes emerged from the…

  6. Factors Related to the Achievement and Adjustment of Young African American Children.

    ERIC Educational Resources Information Center

    Luster, Tom; McAdoo, Harriette Pipes

    1994-01-01

    Data from the National Longitudinal Survey of Youth were used to examine factors related to the achievement and adjustment of 378 African American children in the early elementary grades. Consistent with past research, there was a positive relationship between the number of risk factors children were exposed to and the probability that they were…

  7. Racial Identity, Social Context, and Race-Related Social Cognition in African Americans during Middle Childhood

    ERIC Educational Resources Information Center

    Rowley, Stephanie J.; Burchinal, Margaret R.; Roberts, Joanne E.; Zeisel, Susan A.

    2008-01-01

    This study examined the effect of changes in racial identity, cross-race friendships, same-race friendships, and classroom racial composition on changes in race-related social cognition from 3rd to 5th grade for 73 African American children. The goal of the study was to determine the extent to which preadolescent racial identity and social context…

  8. Relative Spousal Earnings and Marital Happiness among African American and White Women

    ERIC Educational Resources Information Center

    Furdyna, Holly E.; Tucker, M. Belinda; James, Angela D.

    2008-01-01

    The distinctive economic histories of African American and White wives suggest that involvement in household income production holds contextually situated unique meanings for these groups. Yet research has not addressed racial differences in the effects of relative earnings on marital well-being. Surveying 431 employed wives in 21 U.S. cities, we…

  9. Mechanisms of Family Impact on African American Adolescents' HIV-Related Behavior

    ERIC Educational Resources Information Center

    Kogan, Steven M.; Brody, Gene H.; Gibbons, Frederick X.; Chen, Yi-fu; Grange, Christina M.; Simons, Ronald L.; Gerrard, Meg; Cutrona, Carolyn E.

    2011-01-01

    A longitudinal model that tested mediating pathways between protective family processes and HIV-related behavior was evaluated with 195 African American youth. Three waves of data were collected when the youth were 13, 15, and 19 years old. Evidence of mediation and temporal priority were assessed for 3 constructs: academic engagement, evaluations…

  10. Racism-Related Stress and Ethnic Identity as Determinants of African American College Students' Career Aspirations

    ERIC Educational Resources Information Center

    Tovar-Murray, Darrick; Jenifer, Ericka S.; Andrusyk, Jara; D'Angelo, Ryan; King, Tia

    2012-01-01

    Drawing primarily on the construct of psychological buffer, the purpose of this study was to explore the extent to which racism-related stress and ethnic identity are determinants of career aspirations. A total of 163 African American college students from a predominately White Midwestern university participated in the study. A moderation…

  11. Earthquake Production by Subduction Zones is Not Linear in Relative Plate Velocity

    NASA Astrophysics Data System (ADS)

    Bird, P.; Kagan, Y. Y.; Jackson, D. D.; Schoenberg, F. P.; Werner, M. J.

    2007-12-01

    The ratio of \\{long-term-average seismic moment production per unit length of plate boundary\\} to \\{relative plate velocity\\} is determined by the "coupled thickness" of seismogenic lithosphere, and also by elastic moduli and geometric factors that are fairly well known. It is generally assumed that coupled thickness is constant within a given class of plate boundary, such as Bird's [2003, G3]: CCB Continental Convergent Boundary, CRB Continental Rift Boundary, CTF Continental Transform Fault, OCB Oceanic Convergent Boundary, OSR Oceanic Spreading Ridge, OTF Oceanic Transform Fault, or SUB Subduction zone. However, Bird et al. [2002, Geodyn. Ser.] and Bird & Kagan [2004, BSSA] found two exceptions: OSR and OTF both have greater coupled thickness at low relative plate velocities. We test for variation of coupled thickness with relative plate velocity in each of the 7 classes of plate boundary. We use shallow (<70 km) earthquakes from the Harvard CMT catalog, 1982.01.01-2007.03.31, above magnitude MW threshold of 5.51 or 5.66. In order to reduce the influence of aftershock swarms, we estimate the probability of independence of each earthquake according to the likelihood stochastic declustering method of Kagan & Jackson [1991; GJI] and use this as a weight. We use the algorithm of Bird & Kagan [2004, BSSA] to assign 95% of shallow earthquakes to plate boundary steps and plate boundary classes, rejecting all earthquakes that fall into one of the 13 orogens of Bird [2003, G3]. We order the plate-boundary steps outside orogens in each class by relative plate velocity according to the PB2002 model of Bird [2003]. Then, we plot cumulative earthquake count as a function of cumulative model tectonic moment (assuming constant coupled thickness and other parameters within each plate boundary class). The null hypothesis is a linear relation; we use 2 measures (Kolmogorov-Smirnov, and Cramer-von Mises) to quantify departures from this line. We use 10,000 simulations of each

  12. Relative Motion of Nubia Plate with Respect to West Africa, Congo and Kalahari Cratons

    NASA Astrophysics Data System (ADS)

    Njoroge, M. W.

    2015-12-01

    The Nubia plate is normally considered to be a rigid plate and as such used in the realization of terrestrial reference frame. Gondwana breakup plate reconstruction, the Cameroon volcanic line, seismicity, and the morphology of the Okavango rift zone (ORZ) suggest the presence of internal deformation within the Nubia plate. To test this hypothesis, six different reference frames were developed from the velocity field of three individual regions (West, Central and South), and of different combinations of them (West+Central, South+Central, and Nubia as a whole). The residual velocities with respect to these references frame help us understand the presence of the relative motion between the different regions thus the stability of the plate. To realize the reference frames, all the publicly available GPS data within the "stable" Nubia plate was processed. Given the small relative velocity, it is important to eliminate eventual biases in the analysis and to have good estimates of uncertainty of the observed velocities. For this reason, velocities were analyzed, and rate uncertainties computed using the Allan variance of rate (AVR) technique, accounting for colored noise. Although geological and geophysical studies indicate the possibility of internal deformation within Nubia, the results of this study shows that the current GPS network is not capable to identify intraplate deformation and within uncertainties Nubia is a single plate. As final note, both the color of the noise and the amplitude of the annual signal of each time series as function of latitude and climatic region were analyzed. The study shows that the noise is approximately flicker for all the good stations independently of the location. On the contrary, the amplitude of the annual signal is strongly dependent on the climate of the regions.

  13. Tectonic implications of post-30 Ma Pacific and North American relative plate motions

    USGS Publications Warehouse

    Bohannon, R.G.; Parsons, T.

    1995-01-01

    The Pacific plate moved northwest relative to North America since 42 Ma. The rapid half rate of Pacific-Farallon spreading allowed the ridge to approach the continent at about 29 Ma. Extinct spreading ridges that occur offshore along 65% of the margin document that fragments of the subducted Farallon slab became captured by the Pacific plate and assumed its motion proper to the actual subduction of the spreading ridge. This plate-capture process can be used to explain much of the post-29 Ma Cordilleran North America extension, strike slip, and the inland jump of oceanic spreading in the Gulf of California. Much of the post-29 Ma continental tectonism is the result of the strong traction imposed on the deep part of the continental crust by the gently inclined slab of subducted oceanic lithosphere as it moved to the northwest relative to the overlying continent. -from Authors

  14. Paleocene emergence of elephant relatives and the rapid radiation of African ungulates

    PubMed Central

    Gheerbrant, Emmanuel

    2009-01-01

    Elephants are the only living representatives of the Proboscidea, a formerly diverse mammalian order whose history began with the 55-million years (mys) old Phosphatherium. Reported here is the discovery from the early late Paleocene of Morocco, ca. 60 mys, of the oldest and most primitive elephant relative, Eritherium azzouzorum n.g., n.sp., which is one of the earliest known representatives of modern placental orders. This well supported stem proboscidean is extraordinarily primitive and condylarth-like. It provides the first dental evidence of a resemblance between the proboscideans and African ungulates (paenungulates) on the one hand and the louisinines and early macroscelideans on the other. Eritherium illustrates the origin of the elephant order at a previously unknown primitive stage among paenungulates and “ungulates.” The primitive morphology of Eritherium suggests a recent and rapid paenungulate radiation after the Cretaceous-Tertiary boundary, probably favoured by early endemic African paleoecosystems. At a broader scale, Eritherium provides a new old calibration point of the placental tree and supports an explosive placental radiation. The Ouled Abdoun basin, which yields the oldest known African placentals, is a key locality for elucidating phylogeny and early evolution of paenungulates and other related endemic African lineages. PMID:19549873

  15. Seismic and Geodynamic Constraints on Compositional Heterogeneity in the Lower Mantle: Implications for Deeply-Rooted Hot Upwellings Under the African and Pacific Plates

    NASA Astrophysics Data System (ADS)

    Forte, A. M.; Glisovic, P.; Rowley, D. B.; Simmons, N. A.; Grand, S. P.; Lu, C.

    2014-12-01

    We present the results of a series of tests that probe the possible existence of compositionally distinct material in the central core of the LLSVPs under the African and Pacific plates using tomography-based mantle flow models that employ several independently-derived viscosity profiles (Mitrovica & Forte 2004, Behn et al. 2004, Steinberger & Calderwood 2006, Forte et al. 2010). We also consider four global tomography models derived from seismic shear velocity data alone (Grand 2002, Panning & Romanowicz 2006, Kustowski et al. 2008, Ritsema et al. 2011). The possible combinations of viscosity and tomography models yield 16 different tests for compositional heterogeneity inside the LLSVPs. In all tests we begin with a mineral physical scaling between lower-mantle shear velocity and density anomalies that assumes thermal effects are dominant everywhere, including within the LLSVPs. We find it is not possible, in any of the tests, to obtain a satisfactory fit to surface geodynamic data, especially the global, long-wavelength gravity anomalies and space-geodetic inferences of excess CMB flattening with a purely thermal interpretation of lower-mantle heterogeneity. If we introduce compositionally-distinct material in the central portions of the LLSVPs, all tests show a notable improvement in the fit to the gravity anomaly and CMB ellipticity data. An optimal reconciliation of the gravity and CMB data is obtained by extending compositional heterogeneity upwards, with maximum-amplitude in the seismic D"-layer and tapering off to negligible values in the mid-mantle. A robust assessment of the dynamical impact of this deeply-rooted compositional heterogeneity is obtained with maps of "mean" convective flow, by averaging the results of all 16 test cases. We find (see map below) dominant lower-mantle upwellings below the axis of the East Pacific Rise (EPR), and under the Caroline Islands in the Western Pacific. Under the African plate we find large-scale upwellings under the

  16. The role of the African-American physician in reducing traffic-related injury and death among African Americans: consensus report of the National Medical Association.

    PubMed Central

    Daniels, Fernando; Moore, Wayne; Conti, Christopher; Norville Perez, Lucille C.; Gaines, Beverly M.; Hood, Rodney G.; Swain, Ian J. J.; Williams, Rudolph; Burgess, Chaka T.

    2002-01-01

    ISSUE: Traffic-related injuries and fatalities disproportionately affect the African American community. These high rates of traffic-related death and injury among African Americans manifest in multiple areas of traffic safety, including: Failure to use seat belts and child restraints. High incidence of alcohol-impaired driving. Failure to follow child passenger and seat belt safety laws and recommendations. High rates of pedestrian accidents, ofen brought on by impairments of drivers and/or pedestrians. Research indicates that national public information campaigns, with general messages only slightly modified for African American audiences, have not been culturally appropriate or effective in changing traffic safety behavior. In addition, traditional distribution mechanisms for these messages have not effectively reached the target population. Evidence suggests that in the African American community, there is a pervasive lack of knowledge of the devastating impact of traffic-related accidents on the overall health status of the community. This lack of information has resulted in a tragic cycle, in which parents fail to model safe operation of motor vehicles, and generation after generation copy this behavior, increasing the community's vulnerability to serious injuries and untimely deaths. This trend toward improper traffic safety habits among African Americans persists despite federal, state and local laws to enforce and promote sound traffic safety practices. OBJECTIVE: To study the existence of disparities in traffic-related injury and death among African Americans and to determine what kinds of traffic safety messages and campaigns will be effective in encouraging African Americans to respond to safety laws in sufficient numbers to reduce the disproportionately high rate of injury and death. Traffic safety issues were examined to effectively recommend policy, address barriers, best practices, and intervention strategies for the National Medical Association

  17. Relative growth of the limbs and trunk in the African apes.

    PubMed

    Shea, B T

    1981-10-01

    Examination of relative growth and allometry is important for our understanding of the African apes, as they represent a closely related group of species of increasing body size. This study presents a comparison of ontogenetic relative growth patterns of some postcranial dimensions in Pan paniscus, Pan troglodytes, and Gorilla gorilla. Interspecific proportion differences among the three species are also analyzed. It is stressed that reliable ontogenetic information can only be obtained if subadults are examined-growth data cannot be inferred from static adult scaling. Results indicate that some postcranial relative growth patterns are very similar in the three species, suggesting differential extrapolation of a common growth pattern, whereas for other proportion comparisons the growth trends differ markedly among the species, producing distinct shape differences in the adults. Interspecific shape changes among the three species are characterized by positive allometry of chest girth and negative allometry of body height and leg length. It is suggested that relative decrease of leg length with increasing body size among the African pongids might be expected on biomechanical grounds, in quadrupedal terrestrialism. Relative to body weight or trunk length, the limbs of the bonobo (Pan paniscus) are longer than in the common chimpanzee or the gorilla, with a lower intermembral index. This may most closely resemble the primitive condition for the African apes. PMID:7325219

  18. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  19. Knowledge, Beliefs and Behaviours Related to STD Risk, Prevention, and Screening among a Sample of African American Men and Women

    ERIC Educational Resources Information Center

    Uhrig, Jennifer D.; Friedman, Allison; Poehlman, Jon; Scales, Monica; Forsythe, Ann

    2014-01-01

    Objective: Current data on sexually transmitted disease (STD) among African Americans show significant racial/ethnic disparities. The purpose of this study was to explore knowledge, attitudes, beliefs, and behaviours related to STD risk, prevention, and testing among African American adults to help inform the development of a health communication…

  20. The driving mechanism of plate tectonics: Relation to age of the lithosphere at trenches

    NASA Astrophysics Data System (ADS)

    Carlson, R. L.; Hilde, T. W. C.; Uyeda, S.

    1983-04-01

    Sea-floor age-depth and age-trench-depth relations suggest that the oceanic lithosphere continues to thicken and subside with age beyond 80 Ma. If so, slab-pull (FS) and ridge-push (FR) forces can be calculated from the age of the sea floor at trenches (t), and if the shear stress acting on the base of the plate increases with absolute velocity (νa), the approximate force balance equation isFD1 Dva2=Svat32+Rt where D, S and R are constants related to drag, slab pull and ridge push, respectively. The relation between velocity and age is FD2 va2=S‧vat12+R‧ We have tested this model by linear regression using rate and age data for 15 trenches: FD3 va(mm/a)2=(9.20±.32)vat12+(26±250) The strength of this correlation (r² = 0.98) is strong evidence in favor of the validity of this simple model. These results suggest that ridge push is just sufficient to overcome drag at the base of the plate, and does not contribute significantly to the motions of oceanic plates, though the value of R‧ is consistent with the motions of plates not attached to subducted slabs.

  1. Cannabis Use Frequency and Use-Related Impairment among African American and White Users: The Impact of Cannabis Use Motives

    PubMed Central

    Shah, Sonia M.; Dean, Kimberlye E.; Zvolensky, Michael J.

    2015-01-01

    Objectives Cannabis use motives are differentially related to cannabis-related impairment and coping motives appear to have the strongest relation to use-related impairment. However, it is currently unknown whether African American individuals differ from White persons in reasons for using cannabis. It is also unknown whether motives’ relations to cannabis use and related impairment vary as a function of race. The present study examined the role of race on cannabis use motives and tested whether motives’ relations with cannabis use and related impairment differed by race. Design The sample consisted of 111 (67.6% non-Hispanic White, 32.4% African American) current cannabis-using adults. Results African American participants did not significantly differ from White participants on cannabis use frequency or use-related impairment. African American participants endorsed more social motives than White participants. Race interacted with social, coping, and conformity motives to predict cannabis-related impairment such that these motives were positively related to cannabis impairment among African American, but not White, participants. Conclusion Although African American and White participants do not differ in their cannabis use frequency or cannabis-related impairment, they appear to use cannabis for different reasons. Further, conformity, coping, and social motives were differentially associated with cannabis-related impairment as a function of race. Findings suggest motives for cannabis use should be contexualized in the context of race. PMID:26264291

  2. Impact of disaster-related mortality on gross domestic product in the WHO African Region

    PubMed Central

    Kirigia, Joses M; Sambo, Luis G; Aldis, William; Mwabu, Germano M

    2004-01-01

    Background Disaster-related mortality is a growing public health concern in the African Region. These deaths are hypothesized to have a significantly negative effect on per capita gross domestic product (GDP). The objective of this study was to estimate the loss in GDP attributable to natural and technological disaster-related mortality in the WHO African Region. Methods The impact of disaster-related mortality on GDP was estimated using double-log econometric model and cross-sectional data on various Member States in the WHO African Region. The analysis was based on 45 of the 46 countries in the Region. The data was obtained from various UNDP and World Bank publications. Results The coefficients for capital (K), educational enrolment (EN), life expectancy (LE) and exports (X) had a positive sign; while imports (M) and disaster mortality (DS) were found to impact negatively on GDP. The above-mentioned explanatory variables were found to have a statistically significant effect on GDP at 5% level in a t-distribution test. Disaster mortality of a single person was found to reduce GDP by US$0.01828. Conclusions We have demonstrated that disaster-related mortality has a significant negative effect on GDP. Thus, as policy-makers strive to increase GDP through capital investment, export promotion and increased educational enrolment, they should always keep in mind that investments made in the strengthening of national capacity to mitigate the effects of national disasters expeditiously and effectively will yield significant economic returns. PMID:15113453

  3. Impact of disaster-related mortality on gross domestic product in the WHO African Region.

    PubMed

    Kirigia, Joses M; Sambo, Luis G; Aldis, William; Mwabu, Germano M

    2004-03-15

    BACKGROUND: Disaster-related mortality is a growing public health concern in the African Region. These deaths are hypothesized to have a significantly negative effect on per capita gross domestic product (GDP). The objective of this study was to estimate the loss in GDP attributable to natural and technological disaster-related mortality in the WHO African Region. METHODS: The impact of disaster-related mortality on GDP was estimated using double-log econometric model and cross-sectional data on various Member States in the WHO African Region. The analysis was based on 45 of the 46 countries in the Region. The data was obtained from various UNDP and World Bank publications. RESULTS: The coefficients for capital (K), educational enrolment (EN), life expectancy (LE) and exports (X) had a positive sign; while imports (M) and disaster mortality (DS) were found to impact negatively on GDP. The above-mentioned explanatory variables were found to have a statistically significant effect on GDP at 5% level in a t-distribution test. Disaster mortality of a single person was found to reduce GDP by US$0.01828. CONCLUSIONS: We have demonstrated that disaster-related mortality has a significant negative effect on GDP. Thus, as policy-makers strive to increase GDP through capital investment, export promotion and increased educational enrolment, they should always keep in mind that investments made in the strengthening of national capacity to mitigate the effects of national disasters expeditiously and effectively will yield significant economic returns. PMID:15113453

  4. Relative and Absolute Plate Motions, Mantle Plumes and Volcanism in the Arctic region

    NASA Astrophysics Data System (ADS)

    Gaina, C.; Torsvik, T. H.

    2012-04-01

    Seafloor spreading in the North Atlantic ocean from Mesozoic until present day involved relative motion between three major tectonic plates: North America, Greenland and Eurasia and a number of microplates. Relative motions between these tectonic plates and movement of northern Pacific terranes since the Jurassic led to the development of the Arctic region as we know it today. Studying the connection between the two realms involve good knowledge of the development of the North Atlantic and Arctic margins and oceanic basins and ideally, model uncertainties. Here we review the kinematics of North Atlantic and asses the implications of different models for locating the plate boundaries in the Arctic. One set of models implies extension before opening of the Eurasia basin and we postulate that this was accommodated in the proximity of Alpha- Mendeleev Ridge. The origin of (mainly) Cretaceous large igneous activity in the central Arctic (the Alpha Mendeleev Ridge) and in the proximity of rifted margins, the so-called HALIP, is still debated. New models of global plate circuits and the connection with deep mantle are used to re-evaluate a possible link between the Arctic volcanism and mantle plumes.

  5. Emotional adjustment and distressed interpersonal relations among low-income African American mothers: moderating effects of demanding kin relations.

    PubMed

    Taylor, Ronald D; Budescu, Mia

    2013-01-01

    Association of mothers' emotional adjustment and negative kin relations with distressed interpersonal relations was examined. Among 115 low-income African American mothers, relationship of depressive symptoms, self-esteem, and demanding kin relations with psychological control and stressful interpersonal relations was assessed. Depressive symptoms and demanding kin relations were positively associated with mothers' use of psychological control in parenting. Interaction of self-esteem with demanding kin relations revealed that self-esteem was negatively associated with psychological control for mothers with high-demanding kin relations but not for mothers with low-demanding kin relations. Mothers' depressive symptoms and demanding kin relations were positively associated with their stressful interpersonal relations. Findings were discussed in terms of the need for research on the beneficial and detrimental aspects of families' social network. PMID:23356357

  6. HIV-related stigma among African, Caribbean, and Black youth in Windsor, Ontario.

    PubMed

    Mihan, Robert; Kerr, Jelani; Maticka-Tyndale, Eleanor

    2016-01-01

    HIV-related stigma has been shown to undermine prevention, care, treatment, and the well-being of people living with HIV. A disproportion burden of HIV infection, as well as elevated levels of HIV-related stigma, is evidenced in sub-Saharan African (SSA) and African-diasporic populations. This study explores factors that influence HIV-related stigma among 16- to 25-year-old youth residing in a Canadian city who identify as African, Caribbean, or Black. Stigma, as rooted in cultural norms and beliefs and related social institutions, combined with insights from research on stigma in SSA and African-diasporic populations, guided the development of a path analytic structural equation model predicting levels of HIV-related stigmatizing attitudes. The model was tested using survey responses of 510 youth to estimate the direct and indirect influences of ethno-religious identity, religious service attendance, time in Canada, HIV/AIDS knowledge, HIV-testing history, sexual health service contact, and gender on HIV-related stigma. Statistically significant negative associations were found between levels of stigma and knowledge and HIV-testing history. Ethno-religious identity and gender had both direct and indirect effects on stigma. African-Muslim participants had higher levels of stigma, lower knowledge, and were less likely to have been tested for HIV infection than other ethno-religious groups. Male participants had higher levels of stigma and lower knowledge than women. Time in Canada had only indirect effects on stigma, with participants in Canada for longer periods having higher knowledge and less likely to have been tested than more recent arrivals. While the strength of the effect of knowledge on stigmatizing attitudes in this research is consistent with other research on stigma and evaluations of stigma-reduction programs, the path analytic results provide additional information about how knowledge and HIV-testing function as mediators of non

  7. Permian and Pennsylvanian tectonic events in eastern California in relation to major plate motions

    SciTech Connect

    Stevens, C.H.; Sedlock, R. ); Stone, P. )

    1993-04-01

    Northwest-trending basins cutting across older northeast-trending facies belts in eastern California opened by Middle Pennsylvanian time and continued to develop and expand into the Early Permian. Basin development was accompanied by east-vergent thrust-faulting in the Early Permian and was followed by development of northeast-trending folds and regional uplift in middle and Late Permian time. These events have been considered products of long-tern sinistral truncation of the western North American continental margin. Later, in the Late Permian, extensional faulting created small northeast-trending basins in which deposition of terrestrial and shallow-marine rocks occurred. The author consider all late Paleozoic tectonism in eastern California to have been driven by plate interactions along the western margin of North America and to be only indirectly related to the late Paleozoic collision between North America and Gondwana. They propose that the truncated part of North America was part of the Paleo-pacific plate. In Nevada the margin of this plate, along which the Havallah assemblage eventually was emplaced, was convergent, but in California the margin bent sharply and became transform. This fault continued as the Mojave-Sonora mega-shear into Mexico where the oceanic part of the Paleopacific plate was subducted under Gondwana, forming an extensive arc now represented by rocks in S. America.

  8. Racial identity, social context, and race-related social cognition in African Americans during middle childhood.

    PubMed

    Rowley, Stephanie J; Burchinal, Margaret R; Roberts, Joanne E; Zeisel, Susan A

    2008-11-01

    This study examined the effect of changes in racial identity, cross-race friendships, same-race friendships, and classroom racial composition on changes in race-related social cognition from 3rd to 5th grade for 73 African American children. The goal of the study was to determine the extent to which preadolescent racial identity and social context predict expectations of racial discrimination in cross-race social interactions (social expectations). Expectations of racial discrimination were assessed using vignettes of cross-race social situations involving an African American child in a social interaction with European Americans. There were 3 major findings. First, expectations for discrimination declined slightly from 3rd to 5th grade. Second, although racial composition of children's classrooms, number of European American friends, gender, and family poverty status were largely unrelated to social expectations, having more African American friends was associated with expecting more discrimination in cross-racial interactions from 3rd to 5th grade. Third, increases in racial centrality were related to increases in discrimination expectations, and increases in public regard were associated with decreases in discrimination expectations. These data suggest that as early as 3rd grade, children are forming attitudes about their racial group that have implications for their cross-race social interactions. PMID:18999320

  9. Everyday discrimination, diabetes-related distress, and depressive symptoms among African Americans and Latinos with diabetes.

    PubMed

    LeBron, Alana M W; Valerio, Melissa A; Kieffer, Edith; Sinco, Brandy; Rosland, Ann-Marie; Hawkins, Jaclynn; Espitia, Nicolaus; Palmisano, Gloria; Spencer, Michael

    2014-12-01

    It is not known how discrimination might affect diabetes-related distress (DRD), an important correlate of diabetes outcomes. We examined correlates of discrimination and the influence of discrimination on DRD and depressive symptoms (DS) for African Americans and Latinos with type 2 diabetes. We analyzed survey data (n = 157) collected at enrollment into a diabetes management intervention. Using multiple linear regression, we examined correlates of discrimination and the association between discrimination and DRD and DS. Discrimination was significantly associated with higher DRD for Latinos (b 1.58, 95% CI 1.08, 2.31, p < 0.05), but not significant for African Americans (b 0.96, 95% CI 0.59, 1.57). Discrimination was marginally significantly associated with more DS for Latinos (b 1.43, 95% CI 0.97, 2.12, p < 0.10), but not significant for African Americans (b 1.21, 95% CI 0.87, 1.70). These findings suggest the need to address stressors unique to racial/ethnic minorities to improve diabetes-related outcomes. PMID:23689972

  10. The political context of AIDS-related stigma and knowledge in a South African township community.

    PubMed

    Forsyth, Brian; Vandormael, Alain; Kershaw, Trace; Grobbelaar, Janis

    2008-07-01

    The purpose of this study was to examine the presentation of AIDS-related stigma and knowledge within the political context of the South African government's response to the AIDS epidemic. It was during the 2000 - 2004 period that key government officials publicly challenged the orthodox views of HIV/AIDS, with the South African president, Thabo Mbeki, actively positing the primary role of poverty and other socio-economic stressors in the progression of the AIDS epidemic. This discursive position had real-time effects for AIDS policy-making and ultimately delayed the implementation of a national antiretroviral (ARV) rollout programme. Consequently this position was criticised by commentators in the media and elsewhere for contributing to an already widespread climate of AIDS stigmatization and misinformation. To shed more light on these claims we conducted a survey in 2005 in Atteridgeville, a South African township, and compared results with those of a similar survey conducted shortly after ARV medications became available in 2004. Results indicated a reduction in AIDS stigma levels across the 1-year period, and that those participants who endorsed contentious political views (such as those expressed by key government officials) were more likely to have a higher level of AIDS-related stigma than those who disagreed. Nevertheless, this study cautions against drawing a causal relationship between the South African government's position and IDS-stigmatizing attitudes, and suggests that further political and social factors be accounted for in an attempt to gain a fuller understanding of this seemingly complex relationship. PMID:18709210

  11. Statistical tests of additional plate boundaries from plate motion inversions

    NASA Technical Reports Server (NTRS)

    Stein, S.; Gordon, R. G.

    1984-01-01

    The application of the F-ratio test, a standard statistical technique, to the results of relative plate motion inversions has been investigated. The method tests whether the improvement in fit of the model to the data resulting from the addition of another plate to the model is greater than that expected purely by chance. This approach appears to be useful in determining whether additional plate boundaries are justified. Previous results have been confirmed favoring separate North American and South American plates with a boundary located beween 30 N and the equator. Using Chase's global relative motion data, it is shown that in addition to separate West African and Somalian plates, separate West Indian and Australian plates, with a best-fitting boundary between 70 E and 90 E, can be resolved. These results are generally consistent with the observation that the Indian plate's internal deformation extends somewhat westward of the Ninetyeast Ridge. The relative motion pole is similar to Minster and Jordan's and predicts the NW-SE compression observed in earthquake mechanisms near the Ninetyeast Ridge.

  12. Plate heat exchanger performance in a nuclear safety-related service water application

    SciTech Connect

    Bowman, C.F.; Craig, E.F.

    1995-12-31

    In the mid-1980`s the Tennessee Valley Authority installed plate heat exchangers in the safety-related service water system at the Sequoyah Nuclear Plant. These heat exchangers are compact, they can be assembled in place, they require less flow than more conventional heat exchangers, and they are easily cleaned. However, equations to predict thermal performance are not readily available in the open literature. An analytical model was developed to predict performance of the heat exchangers at off-design conditions and to trend thermal performance. Periodic surveillance tests have been performed and the fouling resistance has been calculated based on these tests and the analytical model. Biological fouling of the plates on the raw water side was determined to be greater than expected due to inadequate biocide treatment of the system.

  13. Relation between the Ultrasonic Attenuation and the Porosity of a RTM Composite Plate

    NASA Astrophysics Data System (ADS)

    Duong, N. T.; Duclos, J.; Bizet, L.; Pareige, P.

    We propose a comparative study of X-ray tomography and ultrasonic reflection methods, for determining the porosity of a composite plate realized in LOMC with an industrial process. We measure the attenuation of ultrasound propagating in the thickness by using 10 MHz plane transducer in pulse-echo mode. Comparing these results to the 2D porosity tomographic map allows establishing a relation between attenuation and porosity. A C-scan picture of the plate given by the echoes reflected by the rear surface also provides a local information on the attenuation. Furthermore, we propose a method for the mapping of the reflecting sources as the included bubbles and the interfaces resin/fibers.

  14. The timing of Mediterranean sapropel deposition relative to insolation, sea-level and African monsoon changes

    NASA Astrophysics Data System (ADS)

    Grant, K. M.; Grimm, R.; Mikolajewicz, U.; Marino, G.; Ziegler, M.; Rohling, E. J.

    2016-05-01

    The Mediterranean basin is sensitive to global sea-level changes and African monsoon variability on orbital timescales. Both of these processes are thought to be important to the deposition of organic-rich sediment layers or 'sapropels' throughout the eastern Mediterranean, yet their relative influences remain ambiguous. A related issue is that an assumed 3-kyr lag between boreal insolation maxima and sapropel mid-points remains to be tested. Here we present new geochemical and ice-volume-corrected planktonic foraminiferal stable isotope records for sapropels S1 (Holocene), S3, S4, and S5 (Marine Isotope Stage 5) in core LC21 from the southern Aegean Sea. The records have a radiometrically constrained chronology that has already been synchronised with the Red Sea relative sea-level record, and this allows detailed examination of the timing of sapropel deposition relative to insolation, sea-level, and African monsoon changes. We find that sapropel onset was near-synchronous with monsoon run-off into the eastern Mediterranean, but that insolation-sapropel/monsoon phasings were not systematic through the last glacial cycle. These latter phasings instead appear to relate to sea-level changes. We propose that persistent meltwater discharges into the North Atlantic (e.g., at glacial terminations) modified the timing of sapropel deposition by delaying the timing of peak African monsoon run-off. These observations may reconcile apparent model-data offsets with respect to the orbital pacing of the African monsoon. Our observations also imply that the previous assumption of a systematic 3-kyr lag between insolation maxima and sapropel midpoints may lead to overestimated insolation-sapropel phasings. Finally, we surmise that both sea-level rise and monsoon run-off contributed to surface-water buoyancy changes at times of sapropel deposition, and their relative influences differed per sapropel case, depending on their magnitudes. Sea-level rise was clearly important for

  15. Tectonics and Relative Plate Motions Around the Andaman Sea and Sumatra

    NASA Astrophysics Data System (ADS)

    Eguchi, T.; Murakoshi, T.

    2005-12-01

    There are several R-F-R models of the active back-arc opening system in the Andaman Sea proposed by authors, e.g., Curray et al. (1978), Eguchi et al. (1979), Eguchi (1991), Mantovani et al. (2001) and Nielsen et al. (2004). Most of the previous authors, except Eguchi et al. (1978) and Eguchi (1991), documented NW-SE or NNW-SSE striking relative plate motion at the Central Andaman Rift. Recent multi-beam bathymetry study by GEODYSSEA Project group confirmed the detailed configuration of the ENE-WSW striking Central Andaman Rift and adjacent transcurrent faults. All of data from the marine survey and recent shallow earthquakes as well as their strike-slip type focal mechanisms along the N-S striking fault segment at 95.2E from 11N to 12.5N support the approximate N-S opening at the adjacent Central Andaman Rift. The magnetic anomaly survey data of Curray et al. (1978) suggest that, in the case of N-S opening, the rate becomes 4.0 cm/y, although Curray et al. (1978) proposed the total rate of 3.7 cm/y in the case of NNW-SSE opening. We then studied the realistic geometry of plate boundaries from Sumatra through the Andaman sea including the Central Andaman Rift to Myanmar, using recent seismological data and GPS studies. As is important, the Sundaland is not part of the Eurasia plate as revealed by recent GPS surveys. Furthermore, based on data of GPS velocity vectors w.r.t. Eurasia plate (e.g., Pradirodirdjo et al., 1997; Michel et. al., 2001), we can recognize some differential motion within the NW-SE striking fore-arc block, which is bounded by the Sumatra transcurrent fault and Java trench. The GPS data indicate 'differential motion' in both the trench-parallel and trench-normal directions within the NW-SE striking fore-arc block. We must resolve whether such kind differential movement within the fore-arc block is steady or not, to investigate the detailed spatio-temporal nature of dynamic coupling at the subduction zones with intermittent activity of larger

  16. An Examination of Color-Blind Racism and Race-Related Stress among African American Undergraduate Students

    ERIC Educational Resources Information Center

    Coleman, M. Nicole; Chapman, Stephanie; Wang, David C.

    2013-01-01

    This study examined the role of color-blind racial ideology among a sample of 152 African American undergraduate students in relation to race-related stress. We hypothesized that those who endorsed relatively higher color-blind racial attitudes would experience greater race-related stress because experiences with racism would be interpreted as…

  17. Appropriateness of no-fault compensation for research-related injuries from an African perspective: an appeal for action by African countries.

    PubMed

    Kamalo, Patrick Dongosolo; Manda-Taylor, Lucinda; Rennie, Stuart

    2016-08-01

    Compensation for research-related injuries (RRIs) remains a challenge in the current environment of global collaborative biomedical research as exemplified by the continued reluctance of the US government, a major player in international biomedical research, to enact regulation for mandatory compensation for RRIs. This stance is in stark contrast to the mandatory compensation policies adopted by other democracies like the European Union (EU) countries. These positions taken by the USA and the EU create a nexus of confusion when research is exported to low-income and middle-income countries which have no laws guiding compensation for RRIs. In this paper, we begin by exploring the background to policies concerning RRIs, how they reflect on the traditional dispute resolution mechanisms in African societies, and how this compares with the no-fault compensation model. We then explore the underlying African ethical framework of Ubuntu in the sub-Saharan region, guiding traditional practices of dispute resolution and compensation, and how this framework can help to form the moral justification for no-fault compensation as the preferred compensation model for RRIs for African countries. Finally, we call upon countries in the African Union (AU), to adopt a no-fault policy for compensation of RRIs, and enact it into a regulatory requirement for insurance-based no-fault compensation for biomedical research, which will then be enforced by member states of the AU. PMID:27259545

  18. New Constraints on Baja California-North America Relative Plate Motion Since 11 Ma

    NASA Astrophysics Data System (ADS)

    Bennett, S. E.; Skinner, L. A.; Darin, M. H.; Umhoefer, P. J.; Oskin, M. E.; Dorsey, R. J.

    2013-12-01

    Tectonic reconstructions of the Pacific-North America (PAC-NAM) plate boundary across the Gulf of California and Salton Trough (GCAST) constrain the controversial magnitude of Baja California microplate-North America (BCM-NAM) relative motion since middle Miocene time. We use estimates of total PAC-NAM relative dextral-oblique motion from the updated global plate-circuit model (Atwater and Stock, 2013; GSA Cordilleran Mtg) to resolve the proportion of this motion on faults east of the BCM. Modern GPS studies and offset of late Miocene cross-gulf geologic tie points both suggest that BCM has never been completely coupled to the Pacific plate. Thus, our preferred GCAST reconstruction uses 93% BCM-PAC coupling from the present back to 6 Ma. We assume BCM-PAC coupling of 60% between 6 and 7 Ma, and 25% between 7 and 11 Ma, to avoid unacceptable overlap of continental crustal blocks between Baja California and the Sierra Madre Occidental (on stable NAM). Using these coupling ratios and PAC-NAM stage Euler poles, we determine the azimuth and velocity of individual points on the BCM in 1 million year increments back to 11 Ma. This procedure accounts for minor clockwise rotation of BCM that occurred during oblique rifting, and shows how total BCM-NAM relative motion increases from north to south due to greater distance from the Euler pole. Finer-scale restoration of tectonic blocks along significant (>1 km offset) faults, across extensional (e.g. pull-apart and half-graben) basins, and by vertical-axis rotation is constrained by local geologic and marine-geophysical datasets and accomplished via the open-source Tectonic Reconstruct ArcGIS tool. We find that restoration across the Gulf of California completely closes marine basins and their terrestrial predecessors between 6 and 9 Ma. Latest Miocene opening of these basins was coincident with a ~10° clockwise azimuthal change from 8 to 6 Ma in PAC-NAM relative motion, as revealed by the global plate circuit model. The

  19. Relative Plate Motion Changes Observed in an Analog Freezing-Wax Model

    NASA Astrophysics Data System (ADS)

    Blais, A.; Naar, D. F.

    2004-12-01

    We investigate the tectonic processes related to changes in seafloor spreading velocity using an Oldenburg and Brune (1972; Nature) freezing-wax analog model, which simulates plate tectonic processes at a shorter time scale (minutes instead of millions of years). Using videotape, we run several experiments at 5, 10, 20, 30 and 40 degrees of relative plate motion direction change. Observing the resulting seafloor spreading geometry after a designed change in relative motion, provides insight for understanding the evolution of corresponding examples in the ocean basins, such as the fracture zone bends near magnetic anomaly 34 along the Kane fracture zone in the Atlantic, and near anomaly 20 along the Mendocino fracture zone in the Pacific and the La Boussole fracture zone in the Indian Ocean. In addition, we document the origin, evolution, and eventual extinction of wax microplates forming within the center of a transform fault strand, much in the same manner as proposed by Bird and Naar (1994; Geology) for the presently active Easter and Juan Fernandez microplates along the southern East Pacific Rise. Although the wax analog model has been shown to have geometric and kinematic scaling properties, it has been difficult to show dynamic scaling. Recent work at Cornell by Bowdenschatz and Katz (URL below) with a different kind of wax and analog model has succeeded replicating the ridge and rift morphology associated with fast and slow seafloor spreading. These recent advances suggest that the model is a viable tool in obtaining insight of the rigid and non-rigid processes that occur during reorganizations of divergent and transform plate boundaries.

  20. A Mediational Model of Racial Discrimination and Alcohol-Related Problems Among African American College Students

    PubMed Central

    Boynton, Marcella H; O’Hara, Ross E; Covault, Jonathan; Scott, Denise; Tennen, Howard

    2014-01-01

    Objective: Racial discrimination has been identified as an important predictor of alcohol-related outcomes for African Americans. The goal of the current study was to extend previously found links between lifetime discrimination, alcohol use, and alcohol problems as well as to elucidate the affective mechanisms underlying these associations, as moderated by gender. Method: A multiple-groups structural equation model was computed using survey data collected from 619 students from a historically Black college/university. Results: The final model provided excellent fit to the data, explaining 6% of the variance in alcohol consumption and 37% of the variance in alcohol problems. Discrimination was a significant predictor of alcohol-related problems but not, by and large, level of use. For men, anger—but not discrimination-specific anger—was a significant partial mediator of the link between discrimination and both alcohol use and alcohol problems. Depression partially mediated the link between discrimination and alcohol problems for both men and women. Conclusions: The results suggest that, for African Americans whose drinking leads to drinking-related problems, discrimination and poor affective self-regulation are highly relevant and predictive factors, especially for men. PMID:24650816

  1. Basin filling related to the Philippine Sea Plate motion in Beppu Bay, southwest Japan

    NASA Astrophysics Data System (ADS)

    Yamada, Keitaro; Takemura, Keiji; Kuwae, Michinobu; Ikehara, Ken; Yamamoto, Masanobu

    2016-03-01

    Strike-slip basins are one of the most important accumulation spaces for sediment of terrigenous, biogenic, and volcanic origins, and generally include large amount of event deposits. Although these event deposits are important basin filling process, research on this topic, particularly the effects of event deposits, is insufficient. In this study, we discuss sedimentation features based on grain composition and other properties for ca. 3000 year periods in Beppu Bay, which is strike-slip basin located at the western end of an arc-bisecting dextral fault known as Median Tectonic Line (MTL) associated with the northwestward subduction of the Philippine Sea Plate. This sediment is composed of hemipelagic clay and coarser event layers of turbidites referred to as types A, B, and C; ash layers referred to as type D; and other referred to as type E. The turbidite event layers, which accounted for 92% of the total major event layer, with >1 cm thickness, consist of particles related to volcanism, including hydrothermal activity. The events control the regional filling rate and transportation of coarse and heavy volcaniclastic materials. In particular, type A, which accounted for 73% of the total major event layer thickness, is likely induced by earthquakes related to the MTL, according to its age. As a result, the basin filling processes are controlled mainly by tectonics related to the subduction of the Philippine Sea Plate.

  2. Sex-Related Alcohol Expectancies among African American Women Attending an Urban STI Clinic

    PubMed Central

    Hutton, Heidi E.; McCaul, Mary E.; Norris, Jeanette; Valliant, Julia D.; Abrefa-Gyan, Tina; Chander, Geetanjali

    2014-01-01

    African American women are disproportionately affected by HIV/AIDS and sexually transmitted infections (STIs). Alcohol use is a significant risk factor for HIV/STI acquisition. Sex related alcohol expectancies (SRAE) may partially account for alcohol related risky sexual behaviors. Using qualitative interviews we explored the link between alcohol use and risky sex among 20 African American women attending an STI clinic who had consumed ≥4 alcoholic drinks per drinking day (binge drinking) and/or reported vaginal or anal sex while under the influence of alcohol. Four SRAE emerged which we named: drink for sexual desire, drink for sexual power, drink for sexual excuse, and drink for anal sex. While the desire SRAE has been documented, this study identified three additional SRAEs not currently assessed by expectancy questionnaires. These SRAEs may contribute to high-risk sex when under the influence of alcohol, and suggests the importance of developing integrated alcohol-sexual risk reduction interventions for high-risk women. PMID:25110958

  3. Factors affecting food choice in relation to venison: A South African example.

    PubMed

    Radder, L; le Roux, R

    2005-11-01

    Meat is a universally valued and sought-after source of human nutrition. However, concerns are raised about the health implications of eating too much saturated animal fat. This also applies to South Africa where the high incidence of heart disease and cancer is often linked to consumption of red meat. Despite venison offering a healthy alternative to beef and lamb, its consumption is low. A review of appropriate literature and the perceptions, opinions and preferences of 300 South African consumers resulted in a simplified framework of consumer and market related issues that could influence consumers' preference for wild venison. Consumer-related factors include health considerations, sensory variables, social interactions, familiarity and habit, psychographics and demographics, while the most important market-related issues comprise price, distribution and promotion. An understanding of all these factors is required to better target the promotion of venison as a healthy food choice. PMID:22060937

  4. The 2011 Tohoku-oki Earthquake related to a large velocity gradient within the Pacific plate

    NASA Astrophysics Data System (ADS)

    Matsubara, Makoto; Obara, Kazushige

    2015-04-01

    rays from the hypocenter around the coseismic region of the Tohoku-oki earthquake take off downward and pass through the Pacific plate. The landward low-V zone with a large anomaly corresponds to the western edge of the coseismic slip zone of the 2011 Tohoku-oki earthquake. The initial break point (hypocenter) is associated with the edge of a slightly low-V and low-Vp/Vs zone corresponding to the boundary of the low- and high-V zone. The trenchward low-V and low-Vp/Vs zone extending southwestward from the hypocenter may indicate the existence of a subducted seamount. The high-V zone and low-Vp/Vs zone might have accumulated the strain and resulted in the huge coseismic slip zone of the 2011 Tohoku earthquake. The low-V and low-Vp/Vs zone is a slight fluctuation within the high-V zone and might have acted as the initial break point of the 2011 Tohoku earthquake. Reference Matsubara, M. and K. Obara (2011) The 2011 Off the Pacific Coast of Tohoku earthquake related to a strong velocity gradient with the Pacific plate, Earth Planets Space, 63, 663-667. Okada, Y., K. Kasahara, S. Hori, K. Obara, S. Sekiguchi, H. Fujiwara, and A. Yamamoto (2004) Recent progress of seismic observation networks in Japan-Hi-net, F-net, K-NET and KiK-net, Research News Earth Planets Space, 56, xv-xxviii.

  5. Oceanic Remnants In The Caribbean Plate: Origin And Loss Of Related LIPs.

    NASA Astrophysics Data System (ADS)

    Giunta, G.

    2005-12-01

    The modern Caribbean Plate is an independent lithospheric entity, occupying more than 4 Mkm2 and consisting of the remnants of little deformed Cretaceous oceanic plateau of the Colombia and Venezuela Basins (almost 1 Mkm2) and the Palaeozoic-Mesozoic Chortis continental block (about 700,000 km2), both bounded by deformed marginal belts. The northern (Guatemala and Greater Antilles) and the southern (northern Venezuela) plate margins are marked by collisional zones, whereas the western (Central America Isthmus) and the eastern (Lesser Antilles) margins are represented by convergent boundaries and their magmatic arcs, all involving ophiolitic terranes. The evolutionary history of the Caribbean Plate since the Jurassic-Early Cretaceous encompasses plume, accretionary, and collisional tectonics, the evidence of which has been recorded in the oceanic remnants of lost LIPs, as revealed in: i) the MORB to OIB thickened crust of the oceanic plateau, including its un-deformed or little deformed main portion, and scattered deformed tectonic units; ii) ophiolitic tectonic units of MORB affinity and the rock blocks in ophiolitic melanges; iii) intra-oceanic, supra subduction magmatic sequences with IAT and CA affinities. The Mesozoic oceanic LIPs, from which the remnants of the Caribbean Plate have been derived, have been poorly preserved during various episodes of the intra-oceanic convergence, either those related to the original proto-Caribbean oceanic realm or those connected with two eo-Caribbean stages of subduction. The trapped oceanic plateau of the Colombia and Venezuela Basins is likely to be an unknown portion of a bigger crustal element of a LIP, similar to the Ontong-Java plateau. The Jurassic-Early Cretaceous proto-Caribbean oceanic domain consists of oceanic crust generated at multiple spreading centres; during the Cretaceous, part of this crust was thickened to form an oceanic plateau with MORB and OIB affinities. At the same time, both South and North American

  6. Predictors of HIV-related stigmas among African American and Latino religious congregants

    PubMed Central

    Derose, Kathryn Pitkin; Kanouse, David E.; Bogart, Laura M.; Griffin, Beth Ann; Haas, Ann; Stucky, Brian D.; Williams, Malcolm V.; Flórez, Karen R.

    2015-01-01

    Objectives Inform church-based stigma interventions by exploring dimensions of HIV stigma among African American and Latino religious congregants and how these are related to drug addiction and homosexuality stigmas and knowing someone HIV-positive. Methods In-person, self-administered surveys of congregants 18+ years old across two African American and three Latino churches (n=1235, response rate 73%) in a western US city with high HIV prevalence. Measures included 12 items that captured dimensions of HIV stigma, a 5-item scale that assessed attitudes towards people who are addicted to drugs, a 7-item scale assessing attitudes towards homosexuality, and questions regarding socio-demographics and previous communication about HIV. Results 63.8% of survey participants were women, mean age was 40.2 years, and 34.4% were African American, 16.8% were U.S.-born Latinos, 16.0% were foreign-born, English-speaking Latinos, and 32.9% were foreign-born, Spanish-speaking Latinos. Exploratory and confirmatory factor analyses identified four dimensions of HIV stigma – discomfort interacting with people with HIV (4 items, α=0.86), feelings of shame “if you had HIV” (3 items, α=0.78), fears of rejection “if you had HIV” (3 items, α=0.71) and feelings of blame towards people with HIV (2 items, α=0.65). Across all dimensions, after controlling for socio-demographic characteristics and previous communication about HIV, knowing someone with HIV was associated with lower HIV stigma, and greater stigma concerning drug addiction and homosexuality were associated with higher HIV stigma. Conclusions Congregation-based HIV stigma reduction interventions should consider incorporating contact with HIV-affected people. It may also be helpful to address attitudes toward drug addiction and sexual orientation. PMID:26213890

  7. Seasonal variation in the relative dominance of herbivore guilds in an African savanna.

    PubMed

    Davies, Andrew B; van Rensburg, Berndt J; Robertson, Mark P; Levick, Shaun R; Asner, Gregory P; Parr, Catherine L

    2016-06-01

    African savannas are highly seasonal with a diverse array of both mammalian and invertebrate herbivores, yet herbivory studies have focused almost exclusively on mammals. We conducted a 2-yr exclosure experiment in South Africa's Kruger National Park to measure the relative impact of these two groups of herbivores on grass removal at both highly productive patches (termite mounds) and in the less productive savanna matrix. Invertebrate and mammalian herbivory was greater on termite mounds, but the relative importance of each group changed over time. Mammalian offtake was higher than invertebrates in the dry season, but can be eclipsed by invertebrates during the wet season when this group is more active. Our results demonstrate that invertebrates play a substantial role in savanna herbivory and should not be disregarded in attempts to understand the impacts of herbivory on ecosystems. PMID:27459791

  8. North american--pacific relative plate motion in southern california from interferometry.

    PubMed

    Lyzenga, G A; Golombek, M P

    1986-09-12

    Very long baseline interferometry measurements of baselines crossing the San Andreas fault zone in southern California have provided observational constraints on rates of elastic tectonic strain accumulation. The single site located near this fault (the Jet Propulsion Laboratory site) moves in a direction concordant with the Pacific plate motion vector but at approximately half the net rate relative to North America. This motion agrees approximately in amount with geologically determined displacement rates on the San Andreas fault alone but not with the local strike of the fault. When considered together with complementary geodetic data, these results suggest a complex relation between the short-term accumulation of elastic strain and its permanent accommodation on existing faults. PMID:17756870

  9. Making sense of abstinence: social representations in young Africans' HIV-related narratives from six countries.

    PubMed

    Winskell, Kate; Beres, Laura K; Hill, Elizabeth; Mbakwem, Benjamin Chigozie; Obyerodhyambo, Oby

    2011-09-01

    Despite the prominence of abstinence promotion in HIV prevention for young Africans, there is little documentation concerning its reception and interpretation. With the purpose of informing programmatic practice, we examined how young Africans from six countries with contrasting HIV prevalence rates make sense of abstinence. 'Scenarios from Africa' scriptwriting contests invite young people to contribute ideas for short films about HIV. Using thematic narrative-based approaches, we analyzed a stratified random sample of these narratives written in 2005 by young women and men aged 10-24 years from Senegal, Burkina Faso, South-East Nigeria, Kenya, Namibia and Swaziland. Abstinence was considerably more prominent as a theme in the samples from SE Nigeria, Kenya and Swaziland. It was articulated in relation to conservative Christian sexual morality and in opposition to condom use with particular intensity in SE Nigeria, with stigmatising implications for non-abstainers. However, cross-national commonalities were more striking than differences. Examples of non-stigmatising pro-abstinence messaging highlighted the appeal of discourses of romantic love and future plans across countries and demographic characteristics. The analysis yielded contextual understanding, youth-driven ideas and recommendations to inform comprehensive HIV-prevention efforts. PMID:21787256

  10. Dyslipidaemia related to insulin resistance and cardiovascular disease in South Asian and West African populations.

    PubMed

    Ewang-Emukowhate, Mfon; Perera, Dilinika; Wierzbicki, Anthony S D M

    2014-01-01

    The global burden of diabetes and cardiovascular disease (CVD) is increasing. Obesity is rapidly increasing worldwide and is associated with dyslipidaemia, metabolic syndrome (MetS) and type 2 diabetes (T2DM). Excess risks of T2DM and CVD are found in migrant Indian Asian and West African populations but with increasing urbanization similar changes are occurring in the original populations and are likely to predispose to a large increase in worldwide burden of CVD. Genetic and environmental factors interacting together play a role in the lipid patterns observed. Dyslipidaemia in the MetS associated with insulin resistance is characterised by an atherogenic lipid profile comprising elevated triglycerides, low high density lipoprotein cholesterol (HDL-C) and increased numbers of small dense low density lipoprotein particles. The pattern of dyslipidaemia varies across different ethnic groups with increases in triglycerides and a reduction in HDL-C being the commonest pattern in non-Caucasians. This review surveys the literature on dyslipidaemia in Indian Asian and West African populations and how it relates to CVD risk in those populations. It is important that dyslipidaemia and other conventional risk factors for CVD are adequately addressed and managed especially in high-risk populations. PMID:24953401

  11. Refining the use of cancer-related cultural constructs with African Americans.

    PubMed

    Sanders Thompson, Vetta L; Lewis, Tanisha; Williams, Sha-Lai

    2013-01-01

    An important step in using culture to increase colorectal cancer screening is the development and use of a reliable and valid measure. Measurement items that work well are defined as those that use clear and simple language, do not result in significant missing data, do not yield unexpected frequencies or patterns of association, and capture an important component of the underlying construct. The authors' work to develop such a measure includes cognitive response testing. This article describes 41 African American participants' reactions to and processing of items that have been used in the public health literature to assess cultural attitudes believed to be relevant to colorectal cancer screening. Participants were asked to verbalize thoughts, feelings, interpretations, and ideas that came to mind while examining or responding to 10 to 11 survey items. The results of cognitive response testing suggest negative reactions to items addressing the fatalism construct, concerns about appearing racist when responding to discrimination and mistrust items, and resistance to phrasing or terminology that conveys negative attitudes or frames of reference. When items were framed in a positive way, participants reported less frustration, confusion, and concern for how they would be perceived by others. The responses of older African Americans in this sample were consistent with research previously completed by Pasick et al.; participants questioned the relevance of items related to cultural constructs to health and cancer preventive behaviors. Recommendations for the assessment and use of cultural constructs and items assessing constructs are provided. PMID:21460257

  12. Lactation in Relation to Long-Term Maternal Weight Gain in African-American Women.

    PubMed

    Palmer, Julie R; Kipping-Ruane, Kristen; Wise, Lauren A; Yu, Jeffrey; Rosenberg, Lynn

    2015-06-15

    We assessed the relationship of lactation to long-term maternal weight gain among African-American women, who have a lower prevalence of lactation and a higher prevalence of obesity than other US women. A pregnancy cohort of 3,147 African-American women from the Black Women's Health Study who gave birth for the first time between 1995 and 2003 was followed for 8 years postpartum. Participants provided data on weight, lactation, gestational weight gain, education, diet, and exercise. Mean differences in weight gain were estimated in multivariable models. Overall, lactation was not associated with mean weight gain. However, the association was modified by prepregnancy body mass index (BMI; weight (kg)/height (m)2) (P for interaction=0.03): Among women with BMI<30 prior to the pregnancy, mean weight gain decreased with increasing months of lactation (P for trend<0.01), whereas among obese women (BMI≥30), mean weight gain increased with increasing duration of lactation (P for trend=0.04). Adjusted mean differences for ≥12 months of lactation relative to no lactation were -1.56 kg (95% confidence interval: -2.50, -0.61) among nonobese women and 2.33 kg (95% confidence interval: -0.35, 5.01) among obese women. The differences in postpartum mean weight gain persisted over the 8-year study period. Residual confounding by factors more common in women who breastfeed longer may have influenced the results. PMID:25944887

  13. South African women's conceptualisations of and responses to sexual coercion in relation to hegemonic masculinities.

    PubMed

    Stern, Erin; Buikema, Rosemarie; Cooper, Diane

    2016-01-01

    Despite the documented relationship between hegemonic norms of masculinities and South African men's use of sexual violence, less is known about how women's engagement with norms of masculinity influences their agency in sexually coercive experiences. This study applied a narrative approach to assess how women's understandings of hegemonic male norms affected their perceptions of and responses to sexually coercive experiences. Twenty-five sexual history narrative interviews were conducted with women across five South African provinces representing a range of ages, language and sociocultural backgrounds. Interviews elicited stories of first experiences of sex and the range of sexual relationships through adulthood. Data were analysed using principles of thematic and narrative analysis. Coercive sexual experiences informed many women's normative ideas about men's sexuality including being impulsive, controlling and aggressive. This could underpin women's limited ability to exercise agency and their increased vulnerability to sexual abuse. Some women reported levels of trust and respect in subsequent relationships, which typically involved deconstructing norms of men's use of coercion and moving beyond self-blame and guilt. The findings highlight the need to appreciate the fluid and situated nature of women's agency from a relational perspective in terms of how women condone and challenge gender norms that support men's use of sexual violence in their relationships. PMID:25996075

  14. Evolution of African swine fever virus genes related to evasion of host immune response.

    PubMed

    Frączyk, Magdalena; Woźniakowski, Grzegorz; Kowalczyk, Andrzej; Bocian, Łukasz; Kozak, Edyta; Niemczuk, Krzysztof; Pejsak, Zygmunt

    2016-09-25

    African swine fever (ASF) is a notifiable and one of the most complex and devastating infectious disease of pigs, wild boars and other representatives of Suidae family. African swine fever virus (ASFV) developed various molecular mechanisms to evade host immune response including alteration of interferon production by multigene family protein (MGF505-2R), inhibition of NF-κB and nuclear activating factor in T-cells by the A238L protein, or modulation of host defense by CD2v lectin-like protein encoded by EP402R and EP153R genes. The current situation concerning ASF in Poland seems to be stable in comparison to other eastern European countries but up-to-date in total 106 ASF cases in wild boar and 5 outbreaks in pigs were identified. The presented study aimed to reveal and summarize the genetic variability of genes related to inhibition or modulation of infected host response among 67 field ASF isolates collected from wild boar and pigs. The nucleotide sequences derived from the analysed A238L and EP153R regions showed 100% identity. However, minor but remarkable genetic diversity was found within EP402R and MGF505-2R genes suggesting slow molecular evolution of circulating ASFV isolates and the important role of this gene in modulation of interferon I production and hemadsorption phenomenon. The obtained nucleotide sequences of Polish ASFV isolates were closely related to Georgia 2007/1 and Odintsovo 02/14 isolates suggesting their common Caucasian origin. In the case of EP402R and partially in MGF505-2R gene the identified genetic variability was related to spatio-temporal occurrence of particular cases and outbreaks what may facilitate evolution tracing of ASFV isolates. This is the first report indicating identification of genetic variability within the genes related to evasion of host immune system which may be used to trace the direction of ASFV isolates molecular evolution. PMID:27599940

  15. Past Plate Motions and The Evolution of Earth's Lower Mantle: Relating LLSVPs and Plume Distribution

    NASA Astrophysics Data System (ADS)

    Bull, A. L.; Torsvik, T. H.; Shephard, G. E.

    2015-12-01

    Seismic tomography elucidates broad, low shear-wave velocity structures in the lower mantle beneath Africa and the central Pacific with uncertain physical and compositional origins. The anomalously slow areas, which cover nearly 50% of the core-mantle boundary, are often referred to as Large Low Shear Velocity Provinces (LLSVPs) due to the reduced velocity of seismic waves passing through them. Several hypotheses have arisen to explain the LLSVPs in the context of large-scale mantle convection. One end-member scenario infers a spatial correlation between LLSVP margins at depth and the reconstructed surface eruption sites of hotspots, kimberlites, and Large Igneous Provinces. Such a correlation has been explained by the preferential triggering of plumes at LLSVP margins by impingement of the subducting lithosphere upon the lower thermal boundary layer at the interface between ambient mantle and the higher density structures. This scenario propounds that Earth's plate motion history plays a controlling role in plume development, and that the location, geometry and morphology of plumes may be influenced by the movement of subducting slabs. Here, we investigate what is necessary to create such a pattern of plume distribution in relation to LLSVPs. We consider what effect past plate motions may have had on the evolution of Earth's lower mantle, and discuss the development of mantle plumes in terms of subduction dynamics. We integrate plate tectonic histories and numerical models of mantle convection to investigate the role that subduction history plays in the development and evolution of plumes in the presence of LLSVPs. To test whether an interaction exists between the surface location of subduction and plume eruption sites, and if so, to what degree over time, we apply varying shifts to the absolute reference frame of the plate reconstruction. With this method, we are able to change the location of subduction at the surface and thus the global flow field. This in turn

  16. New and simple plate test for screening relative transfructosylation activity of fungi.

    PubMed

    Dominguez, Ana; Santos, Isabel M; Teixeira, José A; Lima, Nelson

    2006-09-01

    Several microorganisms are reported to have transfructosylation activity due to fructosyltransferase and/or fructofuranosidase activities. However, the search for other fungi with higher transfructosylation activity remains a challenge. So, a presumptive and indirect colorimetric plate assay for the evaluation of transfructosylation activity in fungi was developed which involved the simultaneous determination in the same plate of glucose and fructose released from sucrose. The method entailed the (a) glucose oxidase-peroxidase coupled reaction using phenol and 4-aminoantipyrine for determination of glucose; and (b) fructose dehydrogenase oxidation in the presence of a tetrazolium salt for determination of fructose. The presence of enzymes with transfructosylation activity was identified by the formation of pink (presence of glucose) and blue (presence of fructose) halos around the fungal colony. In conclusion, the results showed that the method is suitable for screening a large number of fungi due to its simplicity, reproducibility and rapidity and also gives a relative quantitative idea of the transfructosylation activity of different fungi species. PMID:17196028

  17. Cretaceous Pacific plate movement beneath SE China: Evidence from episodic volcanism and related intrusions

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Xu, Xisheng; Xia, Yan

    2014-02-01

    Extensive Late Mesozoic igneous rocks in SE China have been widely considered to be generated under the paleo-Pacific tectonic regime, the plate subduction model, however, remains controversial. This study focuses on the Cretaceous volcanic rocks in northwestern Zhejiang Province. Zircon U-Pb age determination indicates that Cretaceous volcanism in northwestern Zhejiang took place at three episodes of 140-130, 130-127 and 123-118 Ma, in good agreement with the coeval lower volcanic series in southeastern Zhejiang, but lacking the episode at 110-88 Ma corresponding to the upper volcanic series. The Cretaceous volcanic rocks in Zhejiang therefore show an oceanward younging trend. In situ zircon Hf isotope analyses of three episodes of volcanics yield ɛHf(t) values of - 11.2 to - 8.7, -4.8 to - 2.4 and - 4.4 to + 2.2, respectively. The entire sequences display typical isotopic features of magma mixing, implying progressive involvement of juvenile component. Based on systematical researches on the Cretaceous volcanic rocks and a series of granitoid plutons in Zhejiang, it is also identified that the juvenile component involvement gradually occurred from the inland to the coast under an enhanced lithospheric extensional tectonic setting. All the observations in this study indicate the northwestward paleo-Pacific plate subduction with episodic slab rollback which triggered the arc system to retreat towards the Pacific Ocean, rather than the southwestward subduction related to the ridge subduction along the Lower Yangtze River belt.

  18. Challenges facing providers of imported malaria-related healthcare services for Africans visiting friends and relatives (VFRs)

    PubMed Central

    2014-01-01

    Background In many non-malarious countries, imported malaria disproportionately affects Africans visiting friends and relatives (VFRs). Most previous research has focused on understanding the knowledge, attitudes and practices of these travellers, but has not examined the quality of prevention, diagnosis and treatment services provided. The aim of this study was to understand the perspective of providers of malaria-related healthcare services to VFRs about factors impacting on the quality of these and to make recommendations about improvements. Methods Thirty semi-structured interviews were conducted with practice nurses providing pre-travel health advice (n = 10), general practitioners (GPs) (n = 10), hospital consultants (n = 3), and community pharmacists (n = 7) working in areas of London with large African communities and a relatively high burden of imported malaria. A thematic analysis of the results was undertaken. Results Time constraints in GPs’ surgeries and competing priorities, lack of confidence in issuing advice on mosquito avoidance, the cost of chemoprophylaxis and travel at short notice prevented the provision of adequate malaria prevention advice. Long GP waiting times, misdiagnoses, lack of disclosure by VFRs about recent travel, and the issue of where malaria treatment should be provided were raised as potential barriers to diagnosis and treatment. Conclusions Some issues raised by respondents are relevant to all travellers, irrespective of their reason for travel. The challenge for healthcare providers to reduce the burden of imported malaria in VFRs is to provide services of sufficient quality to persuade them to adopt these in preference to those with which they may be familiar in their country of birth. Although no single intervention will significantly lower the burden of imported malaria, addressing the issues raised in this research could make a significant impact. PMID:24405512

  19. Perceived Factors that Influence Career Decision Self-Efficacy and Engineering Related Goal Intentions of African American High School Students

    ERIC Educational Resources Information Center

    Austin, Chandra Yvette

    2010-01-01

    This study examined the relationship between specific factors believed to influence career decision self-efficacy and math/science related goal intentions (proxy for engineering related goal intentions) among African American high school students. Minority students generally tend to be underrepresented in such careers, as indicated by the National…

  20. Brief Report: The Number of Sexual Partners and Race-Related Stress in African American Adolescents--Preliminary Findings

    ERIC Educational Resources Information Center

    Stevens-Watkins, Danelle; Brown-Wright, Lynda; Tyler, Kenneth

    2011-01-01

    The current study examined the association between the number of lifetime sexual partners and race-related stress among African American 201 high school juniors and seniors at two urban high schools in the Southeastern region of the country. Students completed the Index of Race-Related Stress-Brief (IRRS-B) and the Youth Risk Behavior Survey…

  1. "No Matter What I Do They Still Want Their Family": Stressors for African American Grandparents and Other Relatives

    ERIC Educational Resources Information Center

    Linsk, Nathan; Mason, Sally; Fendrich, Michael; Bass, Michael; Prubhughate, Priti; Brown, Allene

    2009-01-01

    Grandparents and other relatives increasingly assume the role of primary caregiver to minor children. This study interviewed family members caring for children whose parents were not available due to parental incarceration, other involvement in the criminal justice system, and substance abuse-related issues. Interviews with 25 African American…

  2. Barriers and Bridges to Positive Cross-Ethnic Relations: African American and White Parent Socialization Beliefs and Practices.

    ERIC Educational Resources Information Center

    Hamm, Jill V.

    2001-01-01

    Using interviews and focus groups, lower and middle socioeconomic status (SES) African American parents and middle SES white parents discussed their objectives regarding cross-ethnic relations and how they helped their children forge positive cross-ethnic relations. The groups relied on different methods to promote socialization. Parents' efforts…

  3. Plate tectonics of the Red Sea and East Africa.

    PubMed

    McKenzie, D P; Davies, D; Molnar, P

    1970-04-18

    The relative motion between the plates on each side of the East African Rift Valley can be obtained from the opening of the Red Sea and the Gulf of Aden. The calculated direction of relative motion agrees well with fault plane solutions for earthquakes north of the equator. PMID:16057189

  4. Associations between depression, distress tolerance, delay discounting, and alcohol-related problems in European American and African American college students.

    PubMed

    Dennhardt, Ashley A; Murphy, James G

    2011-12-01

    Although levels of heavy drinking and alcohol-related problems are high in college students, there is significant variability in the number and type of problems experienced, even among students who drink heavily. African American students drink less and experience fewer alcohol-related problems than European American students, but are still at risk, and little research has investigated the potentially unique patterns and predictors of problems among these students. Depression, distress tolerance, and delay discounting have been implicated in adult substance abuse and may be important predictors of alcohol problem severity among college students. We examined the relationship between these variables and alcohol-related problems among African American and European American students (N = 206; 53% female; 68% European American; 28% African American) who reported recent heavy drinking. In regression models that controlled for drinking level, depression, distress tolerance, and delay discounting were associated with alcohol problems among African American students, but only depression was associated with alcohol problems among European American students. These results suggest that negative affect is a key risk factor for alcohol problems among college student drinkers. For African American students, the inability to tolerate negative emotions and to organize their behavior around future outcomes may also be especially relevant risk factors. PMID:21988480

  5. Obliquely convergent plate motion and its relation with forearc sliver movement, El Salvador volcanic arc

    NASA Astrophysics Data System (ADS)

    Tikoff, B.; DeMets, C.; Garibaldi, N.; Hernandez, W.; Hernandez, D.

    2012-12-01

    The magmatic arc in El Salvador is interpreted to result from the subduction of the Cocos plate underneath the Caribbean plate along the Middle America trench. In addition, El Salvador contains a fore-arc sliver that moves 11 mm/yr westward relative to the back-arc. Well-defined strike-slip faults along the magmatic arc accommodate forearc sliver motion, but are offset at several locations by en echelon pull-apart step-overs with abundant normal faults. All basaltic-andesitic magmatic centers (San Miguel, San Vincente, San Salvador, Santa Ana) are located within these step-overs, while the two major rhyolitic calderas (Ilopango, Coatepeque) occur directly along the strike-slip faults. There are two puzzling aspects about the strike-slip tectonism. First, a silicic, shallow magma body that intrudes the San Miguel fault zone (part of the El Salvador fault system) was emplaced syn-tectonically (sigmoidal field and magnetic foliations, subhorizontally plunging magnetic lineations and dextral shear at the microscale). Within the dextrally sheared portion of the intrusion, an obsidian band with a 40Ar/39Ar age of 7.46 Ma indicates that dextral strike-slip tectonism in the Salvadoran arc has been an ongoing process for ~7.5 Ma. This casts significant doubt on whether Cocos ridge subduction (that started ~1 Ma ago) is the cause of the ongoing forearc movement. The potentially more significant problem is that the fore-arc sliver in El Salvador moves 11 mm/yr westward relative to the back-arc despite a nearly orthogonal angle of convergence (with a convergence rate of ~77 mm/yr) near El Salvador and absence of significant frictional coupling along the subduction interface. Further, GPS indicates that the Nicaraguan and Salvadoran forearcs define a semi-rigid sliver moving at nearly the same trench-parallel rates despite along-trench changes in the subduction angle. Consequently, it is tempting to attribute the movement of both forearc slivers to Cocos ridge subduction

  6. HIV-Related Sexual Risk Behavior Among African American Adolescent Girls

    PubMed Central

    Walsh, Kate; McCauley, Jenna; Ruggiero, Kenneth J.; Brown, Jennifer L.; Sales, Jessica M.; Rose, Eve; Wingood, Gina M.; DiClemente, Ralph J.

    2014-01-01

    Abstract Background: Latent class analysis (LCA) is a useful statistical tool that can be used to enhance understanding of how various patterns of combined sexual behavior risk factors may confer differential levels of HIV infection risk and to identify subtypes among African American adolescent girls. Methods: Data for this analysis is derived from baseline assessments completed prior to randomization in an HIV prevention trial. Participants were African American girls (n=701) aged 14–20 years presenting to sexual health clinics. Girls completed an audio computer-assisted self-interview, which assessed a range of variables regarding sexual history and current and past sexual behavior. Results: Two latent classes were identified with the probability statistics for the two groups in this model being 0.89 and 0.88, respectively. In the final multivariate model, class 1 (the “higher risk” group; n=331) was distinguished by a higher likelihood of >5 lifetime sexual partners, having sex while high on alcohol/drugs, less frequent condom use, and history of sexually transmitted diseases (STDs), when compared with class 2 (the “lower risk” group; n=370). The derived model correctly classified 85.3% of participants into the two groups and accounted for 71% of the variance in the latent HIV-related sexual behavior risk variable. The higher risk class also had worse scores on all hypothesized correlates (e.g., self-esteem, history of sexual assault or physical abuse) relative to the lower risk class. Conclusions: Sexual health clinics represent a unique point of access for HIV-related sexual risk behavior intervention delivery by capitalizing on contact with adolescent girls when they present for services. Four empirically supported risk factors differentiated higher versus lower HIV risk. Replication of these findings is warranted and may offer an empirical basis for parsimonious screening recommendations for girls presenting for sexual healthcare services. PMID

  7. Victimization Experiences, Substance Misuse and Mental Health Problems in Relation to Risk for Lethality among African-American and African-Caribbean Women

    PubMed Central

    Sabri, Bushra; Stockman, Jamila K.; Betrand, Desiree; Campbell, Doris W.; Callwood, Gloria B.; Campbell, Jacquelyn C.

    2013-01-01

    The purpose of this study was to investigate the association of intimate partner victimization experiences, mental health, and substance misuse problems with the risk for lethality among women of African descent. Data for this cross-sectional study were derived from a large case-control study examining the relationship between abuse status and health consequences. Women were recruited from primary care, prenatal or family planning clinics in Baltimore and the US Virgin Islands. Logistic regression was used to generate the study findings. Among 543 abused women, physical and psychological abuse by intimate partners, comorbid PTSD and depression symptoms, and PTSD-only problems significantly increased the likelihood of lethality risk. However victims’ substance misuse and depression-only problems were not associated with the risk for lethality. Additionally, PTSD symptoms mediated the relationship between severe victimization experiences and risk for lethality. Practitioners should pay attention to victimization experiences and mental health issues when developing treatment and safety plans. Policies to fund integrated services for African-American and African-Caribbean women with victimization and related mental health issues, and training of providers to identify at-risk women may help reduce the risk for lethality in intimate partner relationships. PMID:23929602

  8. Partner influences and gender-related factors associated with noncondom use among young adult African American women.

    PubMed

    Wingood, G M; DiClemente, R J

    1998-02-01

    We examined the partner influences and gender-related correlates of noncondom use among African American women. The prevalence of noncondom use was 45.3%. Women whose sexual partners were noncondom users were four times more likely to believe that asking their partner to use a condom implied he was unfaithful, three times as likely to have a partner who resisted using condoms, three times more likely to receive AFDC, twice as likely to be sexually nonassertive, three times more likely to believe that it was not difficult to find an "eligible" African American man, and three times as likely to have had one sexual partner. HIV prevention tailored towards African American women should address these partner influences and gender-related factors. PMID:9574497

  9. Responding to AIDS-related bereavement in the South African context.

    PubMed

    Demmer, Craig

    2007-10-01

    AIDS continues to be a death sentence for many individuals living in South Africa where it remains the leading cause of death. Little is currently known about what it is like to experience the loss of a loved one to AIDS from the South African perspective and how to assist individuals who are living in a context vastly different from similarly bereaved individuals in the West. The purpose of this article is to discuss contextual issues that may affect individuals in South Africa who are grieving AIDS-related deaths and to offer preliminary suggestions on how to help these individuals. The author draws on his experience in the province of KwaZulu-Natal working with people affected by the HIV/AIDS epidemic, as well as discussions with practitioners involved in HIV/AIDS care in this region. PMID:17886413

  10. Hormone-related pathways and risk of breast cancer subtypes in African American women.

    PubMed

    Haddad, Stephen A; Lunetta, Kathryn L; Ruiz-Narváez, Edward A; Bensen, Jeannette T; Hong, Chi-Chen; Sucheston-Campbell, Lara E; Yao, Song; Bandera, Elisa V; Rosenberg, Lynn; Haiman, Christopher A; Troester, Melissa A; Ambrosone, Christine B; Palmer, Julie R

    2015-11-01

    We sought to investigate genetic variation in hormone pathways in relation to risk of overall and subtype-specific breast cancer in women of African ancestry (AA). Genotyping and imputation yielded data on 143,934 SNPs in 308 hormone-related genes for 3663 breast cancer cases (1098 ER-, 1983 ER+, 582 ER unknown) and 4687 controls from the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium. AMBER includes data from four large studies of AA women: the Carolina Breast Cancer Study, the Women's Circle of Health Study, the Black Women's Health Study, and the Multiethnic Cohort Study. Pathway- and gene-based analyses were conducted, and single-SNP tests were run for the top genes. There were no strong associations at the pathway level. The most significantly associated genes were GHRH, CALM2, CETP, and AKR1C1 for overall breast cancer (gene-based nominal p ≤ 0.01); NR0B1, IGF2R, CALM2, CYP1B1, and GRB2 for ER+ breast cancer (p ≤ 0.02); and PGR, MAPK3, MAP3K1, and LHCGR for ER- disease (p ≤ 0.02). Single-SNP tests for SNPs with pairwise linkage disequilibrium r (2) < 0.8 in the top genes identified 12 common SNPs (in CALM2, CETP, NR0B1, IGF2R, CYP1B1, PGR, MAPK3, and MAP3K1) associated with overall or subtype-specific breast cancer after gene-level correction for multiple testing. Rs11571215 in PGR (progesterone receptor) was the SNP most strongly associated with ER- disease. We identified eight genes in hormone pathways that contain common variants associated with breast cancer in AA women after gene-level correction for multiple testing. PMID:26458823

  11. Exposed plate interface in the European Alps reveals fabric styles and gradients related to an ancient seismogenic coupling zone

    NASA Astrophysics Data System (ADS)

    Bachmann, Raik; Oncken, Onno; Glodny, Johannes; Seifert, Wolfgang; Georgieva, Viktoria; Sudo, Masafumi

    2009-05-01

    We present observations from a continuous exposure of an ancient plate interface in the depth range of its former seismogenic zone in the central Alps of Europe related to Late Cretaceous-early Tertiary subduction and accretion of the South Penninic lower plate underneath the Adriatic upper plate. The material forming the exposed plate interface zone has experienced flow and fracturing over an extended period of time followed by syncollisional exhumation, thus reflecting a multistage evolution. Fabric formation and metamorphism, however, chiefly record the deformation conditions of the precollisional setting along the plate interface. We identify an unstable slip domain from pseudotachylytes occurring in the temperature range between 200 and 300°C. This zone coincides with a domain of intense veining in the subduction mélange with mineral growth into open cavities, indicating fast, possibly seismic, rupture. Evidence for transient near-lithostatic fluid pressure as well as brittle fractures competing with mylonitic shear zones continues into the region below the occurrence of pseudotachylytes, possibly reflecting a zone of conditionally stable slip. The zone above the unstable slip area is devoid of veins but displays ample evidence of fluid-assisted processes similar to the deeper zone: solution-precipitation creep and dehydration reactions in the mélange matrix, hydration, and sealing of the base of the upper plate. Seismic rupture here is possibly expressed by ubiquitous localized deformation zones. We hypothesize that trenchward sealing of parts of the plate interface as well as reaction-enhanced destruction of upper plate permeability is an important component, localizing the unstable slip zone. This relation may result from the competition of the pervasive, presumably interseismic, pressure solution creep destroying permeability and building elevated fluid pressure until the strength threshold is reached with seismic failure.

  12. Relative time scales reveal multiple origins of parallel disjunct distributions of African caecilian amphibians.

    PubMed

    Loader, Simon P; Pisani, Davide; Cotton, James A; Gower, David J; Day, Julia J; Wilkinson, Mark

    2007-10-22

    Parallel patterns of distribution in different lineages suggest a common cause. Explanations in terms of a single biogeographic event often imply contemporaneous diversifications. Phylogenies with absolute time scales provide the most obvious means of testing temporal components of biogeographic hypotheses but, in their absence, the sequence of diversification events and whether any could have been contemporaneous can be tested with relative date estimates. Tests using relative time scales have been largely overlooked, but because they do not require the calibration upon which absolute time scales depend, they make a large amount of existing molecular data of use to historical biogeography and may also be helpful when calibration is possible but uncertain. We illustrate the use of relative dating by testing the hypothesis that parallel, disjunct east/west distributions in three independent lineages of African caecilians have a common cause. We demonstrate that at least two biogeographic events are implied by molecular data. Relative dating analysis reveals the potential complexity of causes of parallel distributions and cautions against inferring common cause from common spatial patterns without considering the temporal dimension. PMID:17609171

  13. Being selective at the plate: processing dependence between perceptual variables relates to hitting goals and performance.

    PubMed

    Gray, Rob

    2013-08-01

    Performance of a skill that involves acting on a goal object (e.g., a ball to be hit) can influence one's judgment of the size and speed of that object. The present study examined how these action-specific effects are affected when the goal of the actor is varied and they are free to choose between alternative actions. In Experiment 1, expert baseball players were asked to perform three different directional hitting tasks in a batting simulation and make interleaved perceptual judgments about three ball parameters (speed, plate crossing location, and size). Perceived ball size was largest (and perceived speed was slowest) when the ball crossing location was optimal for the particular hitting task the batter was performing (e.g., an "outside" pitch for opposite-field hitting). The magnitude of processing dependency between variables (speed vs. location and size vs. location) was positively correlated with batting performance. In Experiment 2, the action-specific effects observed in Experiment 1 were mimicked by systematically changing the ball diameter in the simulation as a function of plate crossing location. The number of swing initiations was greater when ball size was larger, and batters were more successful in the hitting task for which the larger pitches were optimal (e.g., greater number of pull hits than opposite-field hits when "inside" pitches were larger). These findings suggest attentional accentuation of goal-relevant targets underlies action-related changes in perception and are consistent with an action selection role for these effects. PMID:23163787

  14. Connective Complexity: African American Adolescents and the Relational Context of Kinship Foster Care

    ERIC Educational Resources Information Center

    Schwartz, Ann

    2008-01-01

    Attempts to address racial disproportionality in child welfare must include a focus on the benefits and challenges facing children in kinship care. African American children not only are overrepresented in the child welfare system, but also are placed disproportionately in kinship foster care. Using a sample of 18 African American adolescents ages…

  15. Minority-Related Stressors and Coping Processes among African American College Students

    ERIC Educational Resources Information Center

    Greer, Tawanda M.; Chwalisz, Kathleen

    2007-01-01

    This study is an investigation of stress and coping among African American students at a predominantly White college/university (PWCU) and a Historically Black College/University (HBCU) and their relationship to academic performance. Participants were 203 African American students (101 from a mid-size predominantly White midwestern state…

  16. Grade-Related Changes in the Production of African American English.

    ERIC Educational Resources Information Center

    Craig, Holly K.; Washington, Julie A.

    2004-01-01

    This investigation examined grade as a source of systematic variation in the African American English (AAE) produced by students in preschool through fifth grades. Participants were 400 typically developing African American boys and girls residing in low- or middle-income homes in an urban-fringe community or midsize central city in the…

  17. Recruitment and Retention Strategies Utilized by 1890 Land Grant Institutions in Relation to African American Students

    ERIC Educational Resources Information Center

    Westbrook, Johnnie R.; Alston, Antoine J.

    2007-01-01

    The purpose of this study was to examine the strategies employed by 1890 land grant universities in recruiting and retaining African Americans in agricultural science. Recruitment strategies such as African American agricultural role models, secondary agricultural education, summer enrichment programs, and prior agricultural life experiences were…

  18. Mothers' Academic Gender Stereotypes and Education-Related Beliefs about Sons and Daughters in African American Families

    ERIC Educational Resources Information Center

    Wood, Dana; Kurtz-Costes, Beth; Rowley, Stephanie J.; Okeke-Adeyanju, Ndidi

    2010-01-01

    The role of African American mothers' academic gender stereotype endorsement in shaping achievement-related expectations for and perceptions of their own children was examined. Mothers (N = 334) of 7th and 8th graders completed measures of expectations for their children's future educational attainment, perceptions of their children's academic…

  19. Negative and Positive Peer Influence: Relations to Positive and Negative Behaviors for African American, European American, and Hispanic Adolescents

    ERIC Educational Resources Information Center

    Padilla-Walker, Laura M.; Bean, Roy A.

    2009-01-01

    The purpose of the current study was to examine adolescents' perceptions of negative and positive peer influence (i.e., indirect peer association and direct peer pressure) as they related to adolescent behavior. Regression analyses were conducted using a sample of African American, European American, and Hispanic adolescents (N=1659, M age=16.06,…

  20. Relations between Perceived Competence, Importance Ratings, and Self-Worth among African American School-Age Children

    ERIC Educational Resources Information Center

    Grier, Leslie K.

    2013-01-01

    The purpose of this research was to investigate how domain-specific importance ratings affect relations between perceived competence and self-worth among African American school-age children. Importance ratings have been found to affect the strength of the relationship between perceived competence and self-worth and have implications for…

  1. Adaptive and Challenged Parenting among African American Mothers: Parenting Profiles Relate to Head Start Children's Aggression and Hyperactivity

    ERIC Educational Resources Information Center

    Carpenter, Johanna L.; Mendez, Julia

    2013-01-01

    Research Findings: This study used a within-group research design and person-centered analytic methods to identify multidimensional profiles of parenting styles, parenting practices, and related emotional factors in a sample of 274 African American mothers recruited from Head Start programs in the northeastern and southeastern United States.…

  2. The Psychosocial Adjustment of African American Youth from Single Mother Homes: The Relative Contribution of Parents and Peers

    ERIC Educational Resources Information Center

    Chester, Charlene; Jones, Deborah J.; Zalot, Alecia; Sterrett, Emma

    2007-01-01

    This study examined the relative roles of parents and peers in the psychosocial adjustment of African American youth (7-15 years old) from single mother homes (N = 242). Main effects of both positive parenting and peer relationship quality were found for youth depressive symptoms. In addition, a main effect of peer relationship quality and an…

  3. African American college students' health behaviors and perceptions of related health issues.

    PubMed

    Ford, D S; Goode, C R

    1994-03-01

    The authors identify specific health-related behaviors of African American college students and compare them with the students' perceptions of corresponding health issues. Among students surveyed, the rate of cigarette smoking (4%) was very low compared with smoking rates found in a national survey (14%); but alcohol consumption was relatively high (63%), although lower than the national average of 91%. More men than women smoked, but more women than men reported they drank alcoholic beverages. Most students (90.2%) said they did not usually eat breakfast, 73.6% reported that their diets were not nutritionally balanced, and the majority (55.4%) were not involved in daily physical activity. More than half (63%) of the students reported satisfactorily handling stress, and 74.1% indicated that they were sexually active. Respondents perceived the most important health issues facing college students as HIV/AIDS and sexually transmitted diseases (STDs), birth control, date rape, stress management, suicide, and alcohol and other drugs. PMID:8201133

  4. Immune-Related Functions of the Hivep Gene Family in East African Cichlid Fishes

    PubMed Central

    Diepeveen, Eveline T.; Roth, Olivia; Salzburger, Walter

    2013-01-01

    Immune-related genes are often characterized by adaptive protein evolution. Selection on immune genes can be particularly strong when hosts encounter novel parasites, for instance, after the colonization of a new habitat or upon the exploitation of vacant ecological niches in an adaptive radiation. We examined a set of new candidate immune genes in East African cichlid fishes. More specifically, we studied the signatures of selection in five paralogs of the human immunodeficiency virus type I enhancer-binding protein (Hivep) gene family, tested their involvement in the immune defense, and related our results to explosive speciation and adaptive radiation events in cichlids. We found signatures of long-term positive selection in four Hivep paralogs and lineage-specific positive selection in Hivep3b in two radiating cichlid lineages. Exposure of the cichlid Astatotilapia burtoni to a vaccination with Vibrio anguillarum bacteria resulted in a positive correlation between immune response parameters and expression levels of three Hivep loci. This work provides the first evidence for a role of Hivep paralogs in teleost immune defense and links the signatures of positive selection to host–pathogen interactions within an adaptive radiation. PMID:24142922

  5. Relative rates of evolution in the coding and control regions of African mtDNAs.

    PubMed

    Howell, Neil; Elson, Joanna L; Howell, Corinna; Turnbull, Douglass M

    2007-10-01

    Reduced median networks of African haplogroup L mitochondrial DNA (mtDNA) sequences were analyzed to determine the pattern of substitutions in both the noncoding control and coding regions. In particular, we attempted to determine the causes of the previously reported (Howell et al. 2004) violation of the molecular clock during the evolution of these sequences. In the coding region, there was a significantly higher rate of substitution at synonymous sites than at nonsynonymous sites as well as in the tRNA and rRNA genes. This is further evidence for the operation of purifying selection during human mtDNA evolution. For most sites in the control region, the relative rate of substitution was similar to the rate of neutral evolution (assumed to be most closely approximated by the substitution rate at 4-fold degenerate sites). However, there are a number of mutational hot spots in the control region, approximately 3% of the total sites, that have a rate of substitution greater than the neutral rate, at some sites by more than an order of magnitude. It is possible either that these sites are evolving under conditions of positive selection or that the substitution rate at some sites in the control region is strongly dependent upon sequence context. Finally, we obtained preliminary evidence for "nonideal" evolution in the control region, including haplogroup-specific substitution patterns and a decoupling between relative rates of substitution in the control and coding regions. PMID:17642471

  6. Coping Strategies as Moderators of the Relation between Individual Race-Related Stress and Mental Health Symptoms for African American Women

    ERIC Educational Resources Information Center

    Greer, Tawanda M.

    2011-01-01

    The purpose of this investigation was to examine coping strategies as moderators of the relationship between individual race-related stress and mental health symptoms among a sample of 128 African American women. Coping strategies refer to efforts used to resolve problems and those used to manage, endure, or alleviate distress. Culture-specific…

  7. Developing a guide for community-based groups to reduce alcohol-related harm among African migrants.

    PubMed

    Jaworski, Alison; Brown, Tony; Norman, Catherine; Hata, Kiri; Toohey, Mark; Vasiljevic, Dubravka; Rowe, Rachel

    2016-04-01

    Issue addressed Alcohol-related harm is an issue of concern for African migrant communities living in Australia. However, there has been little information available to guide workers in developing culturally sensitive health promotion strategies. Methods A three-step approach, comprising a literature review, community consultations and an external review, was undertaken to develop a guide to assist organisations and health promotion groups working with African migrant communities to address alcohol-related harms. Discussion There was a high level of agreement between the three steps. Addressing alcohol harms with African migrant communities requires approaches that are sensitive to the needs, structures and experiences of communities. The process should incorporate targeted approaches that enable communities to achieve their resettlement goals as well as strengthening mainstream health promotion efforts. Conclusions The resource produced guides alcohol harm prevention coalitions and workers from the first steps of understanding the influences of acculturation and resettlement on alcohol consumption, through to planning, developing and evaluating an intervention in partnership with communities. So what? This paper advances knowledge by providing a precise summary of Australian African migrant focused alcohol and other drug research to date. It also describes a three-step approach that aimed to incorporate a diversity of community views in the creation of a health promotion and community capacity-building resource. PMID:26726816

  8. A case-control study of menstrual factors in relation to breast cancer risk in African-American women.

    PubMed Central

    Beiler, Jessica S. B.; Zhu, Kangmin; Hunter, Sandra; Payne-Wilks, Kathleen; Roland, Chanel L.; Chinchilli, Vernon M.

    2003-01-01

    Menstrual characteristics may serve as surrogate measures of endogenous estrogen and may be related to breast cancer risk. No previous studies have systematically investigated menstrual factors in relation to the disease in African-American women. This case-control study is aimed to assess the relationship between menstrual factors and breast cancer in African-American women. Cases were 304 African-American women, aged 20-64 living in three Tennessee counties, diagnosed with breast cancer between 1995 and 1998. Controls were selected through random-digit dialing and frequency matched to cases (n=305). Phone interviews were conducted on menstrual factors--age at menarche, time to regularity, cycle length, flow length, age at menopause--and other risk factors. Logistic regression showed that compared to women with short cycle length (<28 days), women with average cycle length > or =28 had decreased risk of breast cancer (odds ratio (OR)=0.60, 95% confidence interval (CI), 0.38-0.94). Dose-response analyses showed decreasing risk with longer cycle length. Results by menopausal status revealed an inverse relationship was shown only in postmenopausal women. No significant associations were observed for other menstrual factors. Findings suggest that cycle length has an inverse association with breast cancer in African-American women that may primarily exist for post-menopausal tumors. PMID:14620704

  9. Bulbous epiphysis and popcorn calcification as related to growth plate differentiation in osteogenesis imperfecta

    PubMed Central

    Brizola, Evelise; McCarthy, Edward; Shapiro, Jay Robert

    2015-01-01

    Summary Background Osteogenesis Imperfecta (OI) is an heritable systemic disorder of connective tissue due to different sequence variants in genes affecting both the synthesis of type I collagen and osteoblast function. Dominant and recessive inheritance is recognized. Approximately 90% of the OI cases are due to mutations in COL1A1/A2 genes. We clinically and radiologically describes an adult male with type III osteogenesis imperfecta who presents a rare bone dysplasia termed bulbous epiphyseal deformity in association with popcorn calcifications. Popcorn calcifications may occur with bulbous epiphyseal deformity or independently. Methods Molecular analysis was performed for COL1A1, COL1A2, LEPRE1 and WNT1 genes. Results An uncommon COL1A1 mutation was identified. Clinical and radiological exams confirmed a distinctive bulbous epiphyseal deformity with popcorn calcifications in distal femurs. We have identified four additional OI patients reported in current literature, whose X-rays show bulbous epiphyseal deformity related to mutations in CR-TAP, LEPRE1 and WNT1 genes. Conclusion The mutation identified here had been previously described twice in OI patients and no previous correlation with bulbous epiphyseal deformity was described. The occurrence of this bone dysplasia focuses attention on alterations in normal growth plate differentiation and the subsequent effect on endochondral bone formation in OI. PMID:26604951

  10. AN INTERVENTION TO REDUCE HIV-RELATED STIGMA IN PARTNERSHIP WITH AFRICAN AMERICAN AND LATINO CHURCHES

    PubMed Central

    Derose, Kathryn Pitkin; Bogart, Laura M.; Kanouse, David E.; Felton, Alexandria; Collins, Deborah Owens; Mata, Michael A.; Oden, Clyde W.; Domínguez, Blanca X.; Flórez, Karen R.; Hawes-Dawson, Jennifer; Williams, Malcolm V.

    2014-01-01

    HIV-related stigma negatively affects prevention and care, and community-based interventions are needed. Here we describe the development of a multi-ethnic, faith-based intervention to reduce HIV stigma that included: educational workshops on HIV, testing, and stigma; peer leader workshops using role plays and drawing on principles of motivational interviewing; a pastor-delivered sermon on HIV that incorporated theological reflection and an imagined contact scenario; and congregation-based HIV testing events. Lessons learned include: partnership development is essential and requires substantial investment; tailoring intervention components to single race-ethnic groups may not be preferable in diverse community settings; and adapting testing processes to be able to serve larger numbers of people in shorter time frames is needed for congregational settings. This development process successfully combined the rigorous application of social science theory and community engagement to yield a multifaceted HIV stigma reduction intervention appropriate for Protestant and Catholic churches in African American and Latino communities. PMID:24450276

  11. Making sense of HIV stigma: Representations in young Africans' HIV-related narratives.

    PubMed

    Winskell, Kate; Holmes, Kathleen; Neri, Elizabeth; Berkowitz, Rachel; Mbakwem, Benjamin; Obyerodhyambo, Oby

    2015-01-01

    In addition to undermining the quality of life of those infected and affected by HIV, HIV-related stigma impedes access to prevention and treatment services, thereby threatening to erode the promise of recent advances in these areas. This paper provides insights into the socio-contextual and sense-making processes that inform HIV stigma through an innovative form of empirical data: creative fictional narratives written by young Africans (aged 10-24) for an HIV-themed scriptwriting competition. From a sample of 586 narratives from six sub-Saharan countries, we selected for illustrative purposes three on account of the complexity of their representation of HIV stigma. We conducted a close reading of each, using stigma theory as a lens. Through their explicit accounts of stigmatising attitudes and behaviours of characters and through implicit contradictions, tensions and ambivalence in their messaging, the narratives provide insights into the symbolic and social processes that create and sustain HIV stigma. Our analysis illuminates the authors' struggles to navigate the cultural resources available to them in their efforts to make sense of HIV, gender and sexuality. It highlights some limitations of current communication efforts and the potential for narrative-based communication approaches to engage with representations that devalue women and people living with HIV. PMID:26132087

  12. What Works? A Qualitative Examination of the Factors Related to the Academic Success of African American Males at a Predominantly White College in the South

    ERIC Educational Resources Information Center

    Robertson, Ray V.; Mason, Danielle

    2008-01-01

    Our study examined the factors related to the retention/academic success of African American males at a mid-sized, regional, predominantly white university in the south. The selected university has an African American male graduation rate, of approximately twenty three percent, which is thirteen percentage points below the national Black male…

  13. Health Emergency 2003: The Spread of Drug-Related AIDS and Hepatitis C among African American and Latinos. Health Emergency Series.

    ERIC Educational Resources Information Center

    Day, Dawn

    This report is the fifth in a series detailing the impact of the injection-related AIDS epidemic on African Americans and Latinos. Ten chapters include: (1) "Health Emergency: The Spread of AIDS among African Americans Who Inject Drugs"; (2) "Health Emergency: The Spread of AIDS Among Latinos Who Inject Drugs"; (3) "A Neglected Opportunity: Drug…

  14. Simultaneous modeling of habitat suitability, occupancy, and relative abundance: African elephants in Zimbabwe

    USGS Publications Warehouse

    Martin, Julien; Chamaille-Jammes, Simon; Nichols, James D.; Fritz, Herve; Hines, James E.; Fonnesbeck, Christopher J.; MacKenzie, Darryl I.; Bailey, Larissa L.

    2010-01-01

    The recent development of statistical models such as dynamic site occupancy models provides the opportunity to address fairly complex management and conservation problems with relatively simple models. However, surprisingly few empirical studies have simultaneously modeled habitat suitability and occupancy status of organisms over large landscapes for management purposes. Joint modeling of these components is particularly important in the context of management of wild populations, as it provides a more coherent framework to investigate the population dynamics of organisms in space and time for the application of management decision tools. We applied such an approach to the study of water hole use by African elephants in Hwange National Park, Zimbabwe. Here we show how such methodology may be implemented and derive estimates of annual transition probabilities among three dry-season states for water holes: (1) unsuitable state (dry water holes with no elephants); (2) suitable state (water hole with water) with low abundance of elephants; and (3) suitable state with high abundance of elephants. We found that annual rainfall and the number of neighboring water holes influenced the transition probabilities among these three states. Because of an increase in elephant densities in the park during the study period, we also found that transition probabilities from low abundance to high abundance states increased over time. The application of the joint habitat–occupancy models provides a coherent framework to examine how habitat suitability and factors that affect habitat suitability influence the distribution and abundance of organisms. We discuss how these simple models can further be used to apply structured decision-making tools in order to derive decisions that are optimal relative to specified management objectives. The modeling framework presented in this paper should be applicable to a wide range of existing data sets and should help to address important ecological

  15. Comparing HIV-related symbolic stigma in six African countries: social representations in young people's narratives.

    PubMed

    Winskell, Kate; Hill, Elizabeth; Obyerodhyambo, Oby

    2011-10-01

    HIV-related symbolic stigma arises from moralistic value judgements attached to people living with HIV and has negative consequences from both public health and human rights perspectives. Relatively little is known about cross-national variation in symbolic stigma. With the purpose of informing stigma reduction efforts within and across settings, we compared social representations of HIV in six African countries with estimated adult HIV prevalence rates ranging from 1 to 33%. Our study used a unique data source, namely a stratified random sample (n = 586, ∼5%) from 11,354 creative ideas contributed from six countries to a continent-wide HIV-related scriptwriting contest held between February and April 2005. The narratives were written by equal numbers of males and females aged 10-24 in urban and rural areas of Swaziland, Namibia, Kenya, South-East Nigeria, Burkina Faso and Senegal. We combined three analytical approaches: descriptive statistics on certain quantifiable characteristics of the narratives, thematic data analysis, and a narrative-based approach. The association of HIV with outsiders ("othering") and preoccupation with the circumstances of infection are more common in lower prevalence countries but vary substantially in tone depending on the sociocultural context. The highest proportion both of moralising narratives and of narratives with pessimistic outcomes come from South-East Nigeria and, to a lesser extent, from Kenya, countries with prevalence levels of 3.9 and 6.1% respectively, in which evangelical Christian movements, including Pentecostalism, have sizeable followings. The data provide a rare cross-cultural overview of symbolic stigma, identify country-specific needs, and point to strategies for future programming. Social representations from the highest prevalence countries, Swaziland and Namibia, and from lower prevalence Burkina Faso offer potential models for the framing of HIV in ways that serve to increase social proximity and counteract

  16. Masculinity and Race-Related Factors as Barriers to Health Help-Seeking Among African American Men.

    PubMed

    Powell, Wizdom; Adams, Leslie B; Cole-Lewis, Yasmin; Agyemang, Amma; Upton, Rachel D

    2016-01-01

    Men's tendency to delay health help-seeking is largely attributed to masculinity, but findings scarcely focus on African American men who face additional race-related, help-seeking barriers. Building principally on reactance theory, we test a hypothesized model situating racial discrimination, masculinity norms salience (MNS), everyday racism (ERD), racial identity, sense of control (SOC), and depressive symptomatology as key barriers to African American men's health help-seeking. A total of 458 African American men were recruited primarily from US barbershops in the Western and Southern regions. The primary outcome was Barriers to Help-Seeking Scale (BHSS) scores. The hypothesized model was investigated with confirmatory factor and path analysis with tests for measurement invariance. Our model fit was excellent [Formula: see text] CFI = 0.99; TLI = 1.00; RMSEA = 0.00, and 90% CI [0.00, 0.07] and operated equivalently across different age, income, and education strata. Frequent ERD and higher MNS contributed to higher BHHS scores. The relationship between ERD exposure and BHHS scores was partially mediated by diminished SOC and greater depressive symptomatology. Interventions aimed at addressing African American men's health help-seeking should not only address masculinity norms but also threats to sense of control, and negative psychological sequelae induced by everyday racism. PMID:27337619

  17. New Evidence that the Emperor Seamount Chain Records Motion of the Pacific Plate Relative to the Deep Mantle

    NASA Astrophysics Data System (ADS)

    Gordon, Richard; Seidman, Lily

    2016-04-01

    A key question for Pacific and circum-Pacific tectonics with implications for mantle convection is whether the Emperor seamount chain records the northward motion of the Pacific plate relative to the deep mantle. To investigate this question, we determine a new Pacific plate paleomagnetic pole for ≈60 Ma BP from the analysis of the skewness of marine magnetic anomaly 26r recording Pacific-Farallon motion in low paleolatitudes. We further update a previously published Pacific plate pole for ≈65 Ma from the analysis of anomalies 27r to 31 by incorporating a larger correction for anomalous skewness. These two poles, along with prior poles for 58 Ma and 72 Ma allow us to test how much, if any, the Hawaiian hotspot moved relative to the spin axis for ≈14 Ma of the ≈30 Ma during which the Emperor chain was formed. We find that the Hawaiian hotspot moved insignificantly southward (4 ±17 mm/a (95% confidence limits)) from 72 Ma to 58 Ma while the Pacific plate moved significantly northward (42 ± 17 mm/a (95% confidence limits)). We further compare the apparent polar wander of the Pacific hotspots with that of the Indo-Atlantic hotspots over the past 65 Ma. The two paths indicate a jump of ≈8° in the position of the spin axis relative to global hotspots between ≈60 Ma and ≈45 Ma presumably due to true polar wander.

  18. Improving Health-Related Quality of Life in Older African-Americans and non-Latino Whites

    PubMed Central

    Jimenez, Daniel E.; Begley, Amy; Bartels, Stephen J.; Alegría, Margarita; Thomas, Stephen B.; Quinn, Sandra C.; Reynolds, Charles F.

    2014-01-01

    Objective To compare the effect of problem solving therapy against a health-promotion intervention (dietary practices) on health-related quality of life (HRQOL) and examine if there is a differential effect on non-Latino Whites and African-Americans between the two interventions. This paper also explores participant characteristics (problem solving style and physical functioning) as potential predictors of HRQOL. Methods Secondary analysis of data from a randomized depression prevention trial involving 247 older adults (154 non-Latino Whites, 90 African-Americans, 3 Asians). Participants were randomly assigned to receive either problem solving therapy for primary care (PST-PC) or coaching in healthy dietary practices (DIET). Results Both PST-PC and DIET improved HRQOL over two years and did not differ significantly from each other. African-Americans in both conditions had greater improvements in mental health-related quality of life (MHRQOL) compared to non-Latino Whites. In addition, higher social problem solving and physical functioning were predictive of improved MHRQOL. Conclusions PST-PC and DIET have the potential to improve health-related quality of life in a culturally relevant manner. Both hold promise as effective and potentially scalable interventions that could be generalized to highly disadvantaged populations in which little attention to HRQOL has been paid. PMID:25171889

  19. Kinematics of the New Zealand plate boundary: Relative motion by GPS across networks of 1000 km and 50 km spacing

    NASA Technical Reports Server (NTRS)

    Meertens, Charles M.; Rocken, Christian; Perin, Barbara; Walcott, Richard

    1993-01-01

    The NASA/DOSE 'Kinematics of the New Zealand Plate Boundary' experiment is a four-year cooperative Global Positioning System (GPS) experiment involving 6 universities and institutions in New Zealand and the United States. The investigation covers two scales, the first on the scale of plates (approximately 1000 km) and the second is on the scale of the plate boundary zone (approximately 50 km). In the first portion of the experiment, phase A, the objective is to make direct measurements of tectonic plate motion between the Australian and Pacific plates using GPS in order to determine the Euler vector of this plate pair. The phase A portion of this experiment was initiated in December 1992 with the first-epoch baseline measurements on the large scale network. The network will be resurveyed two years later to obtain velocities. The stations which were observed for phase A are shown and listed. Additional regional stations which will be used for this study are listed and are part of either CIGNET or other global tracking networks. The phase A portion of the experiment is primarily the responsibility of the UNAVCO investigators. Therefore, this report concentrates on phase A. The first year of NASA funding for phase A included only support for the field work. Processing and analysis will take place with the second year of funding. The second part of the experiemnt measured relative motion between the Australian and Pacific plates across the pate boundary zone between Hokitika and Christchurch on the South Island of New Zealand. The extent and rate of deformation will be determined by comparisons with historical, conventional surveys and by repeated GPS measurements to be made in two years. This activity was the emphasis of the LDGO portion of the study. An ancillary experiment, phase C, concentrated on plate boundary deformation in the vicinity of Wellington and was done as part of training during the early portion of the field campaign. Details of the objectives of the

  20. Maternal Control and Sensitivity, Child Gender, and Maternal Education in Relation to Children's Behavioral Outcomes in African American Families

    PubMed Central

    Tamis-LeMonda, Catherine S.; Briggs, Rahil D.; McClowry, Sandra G.; Snow, David L.

    2009-01-01

    This study examined relationships between mother-child interactions and children's behaviors in 119 urban African American mothers and their 6 - 7 year old children. Interactions during a cooking task and a follow-up child clean-up task were videotaped. Principal components analyses of behaviors during the cooking task yielded two factors in mothers (Sensitivity and Control), and three in children (Task Involvement, Responsiveness, and Communicative). Children's negativity during a clean up task was coded and mothers were interviewed about their children's problem behaviors. Parenting sensitivity was associated with positive child behaviors and parenting control was associated with negative child behaviors. Maternal education was associated with greater maternal sensitivity and less control. Child gender predicted their task involvement, responsiveness, communicativeness, negativity during clean-up, and behavior problems; maternal control and sensitivity mediated some of these relations. Findings underscore heterogeneity of African American parenting and factors that promote positive parenting and children's behavioral adjustment in early childhood. PMID:20161193

  1. Mantle plume related dynamic uplift and plate kinematics: The NE Atlantic case with global implications.

    NASA Astrophysics Data System (ADS)

    Skogseid, Jakob; Khabbaz Ghazian, Reza; Lunt, Ian

    2014-05-01

    At present a pronounced residual depth anomaly (RDA), centred on Iceland, is characterizing the bathymetry of the NE Atlantic region. For the oceanic lithosphere this anomaly represents a <500 to >2500 m elevation difference compared to 'normal' oceanic lithosphere. The observed depth anomaly has since Cochran and Talwani (1978) been ascribed to a 200 -300 km thick moderate thermal anomaly beneath the oceanic lithosphere, the existence of which today has been proven by a sizable low velocity zone on seismic tomography data. The sub-lithosphere low velocities are, however, not limited to the oceanic domain, but also underlie the adjacent continental lithosphere, thus causing a similar magnitude anomalous elevation of the continental shelves and landmasses. The thermal anomaly is presumed to relate to the arrival of the Iceland mantle plume demonstrated by excess Paleocene and Early Eocene magmatism and the formation of the North Atlantic Volcanic Province (NAVP), and subsequent volcanic margin formation. The present width of the RDA compares with the size of the regions that experienced excess magmatism during rifting and breakup, which implies that the sub-lithospheric thermally anomalous body was emplaced in Paleocene time, but still resides in the area. This presentation aims to describe the temporal and spatial development of uplift based on combining plate kinematic modeling with models of lithospheric and plume body thickness development through Late Cretaceous-Paleocene extension, and subsequent seafloor spreading. The model prediction of uplift compares well with descriptions of erosional episodes and depositional sequences off Greenland, in the Northern North Sea, off mid-Norway and in the SW Barents Sea, and represents a mechanism that explains the present elevation of East Greenland as well as western Norway. In a global perspective the close correlation between Large Igneous Provinces (LIP's), the arrival of known mantle plumes and formation of volcanic

  2. Relative potentials of concentrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications

    NASA Technical Reports Server (NTRS)

    Borden, C. S.; Schwartz, D. L.

    1984-01-01

    The purpose of this study is to assess the relative economic potentials of concenrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications in the mid-1990's. Specific objectives of this study are to provide information on concentrator photovoltaic collector probabilistic price and efficiency levels to illustrate critical areas of R&D for concentrator cells and collectors, and to compare concentrator and flat-plate PV price and efficiency alternatives for several locations, based on their implied costs of energy. To deal with the uncertainties surrounding research and development activities in general, a probabilistic assessment of commercially achievable concentrator photovoltaic collector efficiencies and prices (at the factory loading dock) is performed. The results of this projection of concentrator photovoltaic technology are then compared with a previous flat-plate module price analysis (performed early in 1983). To focus this analysis on specific collector alternatives and their implied energy costs for different locations, similar two-axis tracking designs are assumed for both concentrator and flat-plate options.

  3. Prevention-Related Research Targeting African American Alternative Education Program Students

    ERIC Educational Resources Information Center

    Carswell, Steven B.; Hanlon, Thomas E.; Watts, Amy M.; O'Grady, Kevin E.

    2014-01-01

    This article reports on a program of research that examined the background, planning, implementation, and evaluation of an after-school preventive intervention program within an ongoing urban alternative education program targeting African American students referred to the school because of their problematic behavior in regular schools. The…

  4. The Effects of Check & Connect on the School-Related Violent Behaviors of African American Females

    ERIC Educational Resources Information Center

    Seaton, Angela T.

    2010-01-01

    This study assessed the effects of a modified version of Check & Connect, a comprehensive student engagement intervention, on the attendance, behavior, and academic performance of secondary African American females with violent and aggressive behavior problems. In addition, the Student Engagement Instrument (SEI) was used to assess cognitive…

  5. Achievement-Related Casual Attribution: A South African Cross-Cultural Study.

    ERIC Educational Resources Information Center

    Louw, Johann; Louw-Potgieter, Joha

    1986-01-01

    Students from three South African Universities, representing three ethnic groups, explain their perceived success or failure on a class test and rated the importance of casual attributions derived from previous studies. Important factors that emerged were as follow: (1) effort, (2) academic skills, (3) understanding. (Author/LHW)

  6. Africentric Cultural Values: Their Relation to Positive Mental Health in African American Adolescent Girls

    ERIC Educational Resources Information Center

    Constantine, Madonna G.; Alleyne, Vanessa L.; Wallace, Barbara C.; Franklin-Jackson, Deidre C.

    2006-01-01

    The primary purpose of this study was to test a path model exploring the relationships among Africentric cultural values, self-esteem, perceived social support satisfaction, and life satisfaction in a sample of 147 African American adolescent girls. This investigation also examined the possible mediating effects of self-esteem and perceived social…

  7. The Relation among Parental Factors and Achievement of African American Urban Youth

    ERIC Educational Resources Information Center

    Wilson, Clancie Mavello

    2009-01-01

    Research has suggested that low socioeconomic status is a major factor in diminishing academic achievement of African American urban youth; however, there are other factors influencing students' achievement. To examine the other factors that contribute to academic achievement, this study investigated a sample of 60 low-resource middle school…

  8. Sex-Related HIV/AIDS Prevention among African American College Students: Issues for Preventive Counseling.

    ERIC Educational Resources Information Center

    Braithwaite, Ronald; Stephens, Torrance; Sumpter-Gaddist, Bambi W.; Murdaugh, Henry; Taylor, Sandra; Braithwaite, Kisha

    1998-01-01

    Examines condom use during oral and anal sex among 1593 African-American college undergraduates. Findings suggest a high level of concordance between men and women on several measures. However, female participants were more likely to use condoms during oral and anal sex than were males. (Author/MKA)

  9. An Examination of Factors Related to the Academic Performance of African-American College Students

    ERIC Educational Resources Information Center

    Wylie, D'Errico M.

    2012-01-01

    The purpose of this study was to identify factors that were predictive of academic performance of college students at Historically Black Colleges/Universities (HBCUs). The variables of interest included: seating choice, self-esteem, anxiety, stress and study habits. The sample consisted of 201 African-American undergraduate students. Participants…

  10. Friendships Influence Hispanic Students' Implicit Attitudes toward White Non-Hispanics Relative to African Americans

    ERIC Educational Resources Information Center

    Aberson, Christopher L.; Porter, Michael K.; Gaffney, Amber M.

    2008-01-01

    This study examined the role of Hispanic students' friendships with White non-Hispanics (n-Hs) and African Americans (AAs) in predicting implicit and explicit prejudices toward these groups. Participants (N = 73) completed implicit and explicit attitude measures and a friendship questionnaire. Friendships were associated with implicit attitudes…

  11. Factors Related to Aggressive and Violent Behavior among Preadolescent African-American Boys.

    ERIC Educational Resources Information Center

    Shields, Nancy; Pierce, Lois

    Drawing on theoretical and empirical studies, this paper hypothesized that attitudes towards the use of violence and the use of aggressive and violent behavior among preadolescent African American males would be affected by verbal aggression in the home, violence observed in the community, family environment, and peer models. Data on aggressive…

  12. Responding to AIDS-Related Bereavement in the South African Context

    ERIC Educational Resources Information Center

    Demmer, Craig

    2007-01-01

    AIDS continues to be a death sentence for many individuals living in South Africa where it remains the leading cause of death. Little is currently known about what it is like to experience the loss of a loved one to AIDS from the South African perspective and how to assist individuals who are living in a context vastly different from similarly…

  13. Developmental and ethnic issues experienced by emerging adult African American women related to developing a mature love relationship.

    PubMed

    Tyson, Sheryl Y

    2012-01-01

    This qualitative study explored perspectives of emerging adult African American women on the development of mature love relationships. Inductive analysis of focus group interviews, conducted with a purposive sample of 31 African American women, yielded themes related to relationship goals and characteristics, and interpersonal and societal challenges to finding the right partner and developing a mature love relationship. Core categories that emerged from analysis of the discussions were (1) age and relationship goal differences within the emerging adult group, (2) mature love relationship goals and characteristics, (3) interpersonal obstacles to finding the right partner, and (4) societal obstacles to finding the right partner. Two approaches-black womanist/feminist thought (Collins, 2000 ; Walker, 1983 ) and relationship maturity theory (Paul & White, 1990 )-were then combined to explain the influence of historic and contemporary interpersonal and societal factors on developmental and ethnic issues that challenge positive gender identity formation, hasten intimacy maturity, and hinder the development of mature love relationships among emerging adult African American women. For these women, premature responsibility, especially early caregiver burden, was related to the early development of intimacy capacity and the desire for a mature love relationship, to be protected, and to have someone to help carry the load. Interracial dating, negative stereotypic images of African American women, and even positive images of enduring black love relationships posed difficult challenges to positive identity formation and intimacy maturity. A primary challenge was to counteract negative stereotypic images, so that they could develop their own self-identities as women and as relationship partners. PMID:22224965

  14. APOL1 Risk Alleles Are Associated with Exaggerated Age-Related Changes in Glomerular Number and Volume in African-American Adults: An Autopsy Study.

    PubMed

    Hoy, Wendy E; Hughson, Michael D; Kopp, Jeffrey B; Mott, Susan A; Bertram, John F; Winkler, Cheryl A

    2015-12-01

    APOL1 genetic variants contribute to kidney disease in African Americans. We assessed correlations between APOL1 profiles and renal histological features in subjects without renal disease. Glomerular number (N glom) and mean glomerular volume (V glom) were measured by the dissector/fractionator method in kidneys of African-American and non-African-American adults without renal disease, undergoing autopsies in Jackson, Mississippi. APOL1 risk alleles were genotyped and the kidney findings were evaluated in the context of those profiles. The proportions of African Americans with none, one, and two APOL1 risk alleles were 38%, 43%, and 19%, respectively; 38% of African Americans had G1 allele variants and 31% of African Americans had G2 allele variants. Only APOL1-positive African Americans had significant reductions in N glom and increases in V glom with increasing age. Regression analysis predicted an annual average loss of 8834 (P=0.03, sex adjusted) glomeruli per single kidney over the first 38 years of adult life in African Americans with two risk alleles. Body mass index above the group medians, but below the obesity definition of ≥ 30 kg/m(2), enhanced the expression of age-related changes in N glom in African Americans with either one or two APOL1 risk alleles. These findings indicate that APOL1 risk alleles are associated with exaggerated age-related nephron loss, probably decaying from a larger pool of smaller glomeruli in early adult life, along with enlargement of the remaining glomeruli. These phenomena might mark mechanisms of accentuated susceptibility to kidney disease in APOL1-positive African Americans. PMID:26038529

  15. (Im)migrations, Relations, and Identities of African Peoples: Toward an Endarkened Transnational Feminist Praxis in Education

    ERIC Educational Resources Information Center

    Okpalaoka, Chinwe L.; Dillard, Cynthia B.

    2012-01-01

    This article focuses on the sense of what an "African" (American) identity could mean when viewed through the processes of migrations and fluid identities of contemporary African immigrant children as they interact with their African (Americans) peers in schools. The purpose of this article is to use data from a study of West African immigrant…

  16. Relation between energetic and utilization coefficients in the positive plates of automotive lead/acid batteries

    NASA Astrophysics Data System (ADS)

    D'Alkaine, C. V.; Carubelli, A.; Fava, H. W.; Sanhueza, A. C.

    A new experimental method to distinguish between energetic and structural materials and to characterize the manufacturing technology for positive plates in lead/acid batteries is discussed. This new method proposes the evaluation of the energetic β-coefficient from plots of capacity versus very low current densities under galvanostatic conditions and using real-size positive plates in 2.3-6.9 M H 2SO 4 solutions. The results are identical to those obtained previously from potentiostatic measurements, and they fit a new equation as opposed to Peukert's equation. The independence of the β-coefficient with H 2SO 4 concentration indicates that the discharge of PbO 2 to its products proceeds via a solid-state reaction mechanism.

  17. The structure of ion plated films in relation to coating properties

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1985-01-01

    Ion plating is an ion assisted or glow discharge deposition technique, where ions or energetic atoms transfer energy, momentum and charge to the substrate and the growing film in a manner which can be controlled to favorably modify surface, subsurface chemistry, and microstructure. The glow discharge energizing effects from the initial nucleation stages to the final film growth are discussed. As a result, adherence, coherence, internal stresses, density and morphology of the coatings are significantly improved, over the conventional (nonion-assisted) techniques which in turn favorably affect the surface initiated failures caused by friction, wear, erosion, corrosion and fatigue. Ion plated films because of their graded coating/substrate interface, fine, uniform, densely packed film structure also induce a surface strengthening effect which improved the mechanical properties such as yield, tensile strength and fatigue life. Since a uniform, continuous film can be obtained at lower nominal film thickness, this effect is of great importance in solid film lubrication and in corrosion protection.

  18. HIV-related stigma in African and Afro-Caribbean communities in the Netherlands: manifestations, consequences and coping.

    PubMed

    Stutterheim, Sarah E; Bos, Arjan E R; Shiripinda, Iris; de Bruin, Marijn; Pryor, John B; Schaalma, Herman P

    2012-01-01

    HIV-related stigma in African and Afro-Caribbean diaspora communities in the Netherlands was investigated. Interviews with HIV-positive and HIV-negative community members demonstrated that HIV-related stigma manifests as social distance, physical distance, words and silence. The psychological consequences of HIV-related stigma among those diagnosed with HIV reported were emotional pain, sadness, loneliness, anger, frustration and internalised stigma. The social consequences included decreased social network size, limited social support and social isolation, and resulted from not only enacted stigma but also self-imposed social withdrawal. Also, poor treatment adherence was a health-related consequence. People living with HIV employed both problem-focused and emotion-focused coping strategies to mitigate the negative consequences of stigma. Problem-focused coping strategies included selective disclosure, disengagement, affiliating with similar others, seeking social support and, to a lesser extent, activism. Emotion-focused strategies included distraction, positive reappraisal, religious coping, external attributions, disidentification and acceptance. HIV-related stigma clearly permeates African and Afro-Caribbean communities in the Netherlands, and should be targeted for intervention. PMID:21678184

  19. Coffee, tea, and alcohol intake in relation to risk of type 2 diabetes in African American women1234

    PubMed Central

    Boggs, Deborah A; Rosenberg, Lynn; Ruiz-Narvaez, Edward A; Palmer, Julie R

    2010-01-01

    Background: Numerous studies have reported inverse associations of coffee, tea, and alcohol intake with risk of type 2 diabetes, but none has reported results separately among African American women. Objective: We prospectively examined the relation of coffee, tea, and alcohol consumption to diabetes risk in African American women. Design: The study included 46,906 Black Women's Health Study participants aged 30–69 y at baseline in 1995. Dietary intake was assessed in 1995 and 2001 by using a validated food-frequency questionnaire. During 12 y of follow-up, there were 3671 incident cases of type 2 diabetes. Relative risks (RRs) and 95% CIs were estimated by using Cox proportional hazards models adjusted for diabetes risk factors. Results: Multivariable RRs for intakes of 0–1, 1, 2–3, and ≥4 cups of caffeinated coffee/d relative to no coffee intake were 0.94 (95% CI: 0.86, 1.04), 0.90 (95% CI: 0.81, 1.01), 0.82 (95% CI: 0.72, 0.93), and 0.83 (95% CI: 0.69, 1.01), respectively (P for trend = 0.003). Multivariable RRs for intakes of 1–3, 4–6, 7–13, and ≥14 alcoholic drinks/wk relative to never consumption were 0.90 (95% CI: 0.82, 1.00), 0.68 (95% CI: 0.57, 0.81), 0.78 (95% CI: 0.63, 0.96), and 0.72 (95% CI: 0.53, 0.98), respectively (P for trend < 0.0001). Intakes of decaffeinated coffee and tea were not associated with risk of diabetes. Conclusion: Our results suggest that African American women who drink moderate amounts of caffeinated coffee or alcohol have a reduced risk of type 2 diabetes. PMID:20826625

  20. Plate Reconstructions And Mantle Structure In The Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Hafkenscheid, E.; Wortel, M. J. R.; Spakman, W.

    The subduction of the Tethys Ocean has dominated the history of large areas in the Mediterranean and Southern Asia. Tectonic reconstructions for these complex regions inevitably show significant differences. Also Greece and Turkey, at the western end of the Tethyan area, are relatively well studied but still not completely understood. For example, for the several suture zones in Turkey it is not clear whether they once have accommodated the convergence between the African and Eurasian plates, or just the convergence resulting from the closure of smaller back-arc basins. We incorporate independent tomographic images of the present mantle structure in our analysis to put further constraints on the geodynamic evolution here. From tectonic reconstructions, we calculate the Mesozoic-Cenozoic plate velocities and convergence. For the Greece-Turkey region, we use the Northeast-African and Eurasian plate rotations. The deformation of the Aegean trench system is added to these motions. The Volumes of subducted lithosphere estimated from the reconstruc- tions are then compared to those inferred from seismic tomography. Our first results suggest that the convergence between the Northeast African and Eurasian plates has been accommodated by one continuous process of subduction, in spite of the different trench systems that are proposed in the reconstructions. We also investigate whether the location and geometry of the subducted material within the mantle might allow us to assess the absolute motion of the plates involved.

  1. Space use of African wild dogs in relation to other large carnivores.

    PubMed

    Darnell, Angela M; Graf, Jan A; Somers, Michael J; Slotow, Rob; Szykman Gunther, Micaela

    2014-01-01

    Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs. PMID:24896638

  2. Space Use of African Wild Dogs in Relation to Other Large Carnivores

    PubMed Central

    Darnell, Angela M.; Graf, Jan A.; Somers, Michael J.; Slotow, Rob; Szykman Gunther, Micaela

    2014-01-01

    Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs. PMID:24896638

  3. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  4. On the relations between cratonic lithosphere thickness, plate motions, and basal drag

    USGS Publications Warehouse

    Artemieva, I.M.; Mooney, W.D.

    2002-01-01

    An overview of seismic, thermal, and petrological evidence on the structure of Precambrian lithosphere suggests that its local maximum thickness is highly variable (140-350 km), with a bimodal distribution for Archean cratons (200-220 km and 300-350 km). We discuss the origin of such large differences in lithospheric thickness, and propose that the lithospheric base can have large depth variations over short distances. The topography of Bryce Canyon (western USA) is proposed as an inverted analog of the base of the lithosphere. The horizontal and vertical dimensions of Archean cratons are strongly correlated: larger cratons have thicker lithosphere. Analysis of the bimodal distribution of lithospheric thickness in Archean cratons shows that the "critical" surface area for cratons to have thick (>300 km) keels is >6-8 ?? 106 km2 . Extrapolation of the linear trend between Archean lithospheric thickness and cratonic area to zero area yields a thickness of 180 km. This implies that the reworking of Archean crust should be accompanied by thinning and reworking of the entire lithospheric column to a thickness of 180 km in accord with thickness estimates for Proterozoic lithosphere. Likewise, extrapolation of the same trend to the size equal to the total area of all Archean cratons implies that the lithospheric thickness of a hypothesized early Archean supercontinent could have been 350-450 km decreasing to 280-400 km for Gondwanaland. We evaluate the basal drag model as a possible mechanism that may thin the cratonic lithosphere. Inverse correlations are found between lithospheric thickness and (a) fractional subduction length and (b) the effective ridge length. In agreement with theoretical predictions, lithospheric thickness of Archean keels is proportional to the square root of the ratio of the craton length (along the direction of plate motion) to the plate velocity. Large cratons with thick keels and low plate velocities are less eroded by basal drag than small

  5. Slab break-off related to the Pacific-Izanagi ridge and the 50 Ma plate reorganization

    NASA Astrophysics Data System (ADS)

    Whittaker, J. M.; Seton, M.; Flament, N.; Gurnis, M.; Talsma, A. S.; Müller, R. D.

    2011-12-01

    A hemisphere-wide plate reorganization occurred approximately 50 million years ago, causing a plethora of tectonic events in the Pacific, Indian and Atlantic oceans. The ultimate driver of this reorganization, either a plate tectonic/top-down or a mantle flow/bottom-up mechanism, remains unresolved. Top-down mechanisms often invoke a dramatic change in slab pull due to the arrival of a mid ocean ridge or aseismic ridge at a subduction zone. Bottom-up mechanisms require sudden lateral or vertical changes in mantle flow. We use a combination of surface geology, plate reconstructions, forward geodynamic models and seismic tomography to investigate the effect a slab break-off event related to the intersection of the Pacific-Izanagi ridge and the East Asian subduction zone on the 50 Ma plate reorganization. The intersection of an active mid ocean ridge with a subduction zone commonly results in the formation of a slab window. Surface manifestations of an underlying slab window are observed in the geology of southern and central Japan including: the cessation of a major accretion phase in the late Cretaceous; elevated geothermal gradients and heat flux around 55 Ma; and the emplacement of the Okitsu Melange due to underlying hot, buoyant material at 55 Ma. The cessation of granitic plutonism in Korea suggests that subduction along the margin terminated at around 60-50 Ma before restarting again ~42 Ma. We independently reconstructed the now subducted ocean floor in Panthalassa based on the magnetic lineations preserved in the ocean floor in the western Pacific and following a simple, symmetrical spreading regime with inferred intermediate spreading rates. Our plate reconstructions result in the progressively southward arrival of the Pacific-Izanagi ridge parallel to the East Asian margin between 60-50 Ma, consistent with the geological observations listed above. In addition, we carry out a series of forward geodynamic models with imposed surface plate velocities

  6. Ridge push, mantle plumes and the speed of the Indian plate

    NASA Astrophysics Data System (ADS)

    Eagles, Graeme; Wibisono, Affelia D.

    2013-08-01

    The buoyancy of lithospheric slabs in subduction zones is widely thought to dominate the torques driving plate tectonics. In late Cretaceous and early Paleogene times, the Indian plate moved more rapidly over the mantle than freely subducting slabs sink within it. This signal event has been attributed to arrival of the Deccan-Réunion mantle plume beneath the plate, but it is unknown in which proportions the plume acted to alter the balance of existing plate driving torques and to introduce torques of its own. Our plate kinematic analysis of the Mascarene Basin yields a detailed Indian plate motion history for the period 89-60 Ma. Plate speed initially increases steadily until a pronounced acceleration in the period 68-64 Ma, after which it abruptly returns to values much like those beforehand. This pattern is unlike that suggested to result from the direct introduction of driving forces by the arrival of a thermal plume at the base of the plate. A simple analysis of the gravitational force related to the Indian plate's thickening away from its boundary with the African plate suggests instead that the sudden acceleration and deceleration may be related to uplift of part of that boundary during a period when it was located over the plume head. In this instance, torques related to plate accretion and subduction may have contributed in similar proportions to drive plate motion.

  7. Analysis of batch-related influences on injection molding processes viewed in the context of electro plating quality demands

    NASA Astrophysics Data System (ADS)

    Siepmann, Jens P.; Wortberg, Johannes; Heinzler, Felix A.

    2016-03-01

    The injection molding process is mandatorily influenced by the viscosity of the material. By varying the material batch the viscosity of the polymer changes. For the process and part quality the initial conditions of the material in addition to the processing parameters define the process and product quality. A high percentage of technical polymers processed in injection molding is refined in a follow-up production step, for example electro plating. Processing optimized for electro plating often requires avoiding high shear stresses by using low injection speed and pressure conditions. Therefore differences in the material charges' viscosity occur especially in the quality related low shear rate area. These differences and quality related influences can be investigated by high detail rheological analysis and process simulation based on adapted material describing models. Differences in viscosity between batches can be detected by measurements with high-pressure-capillary-rheometers or oscillatory rheometers for low shear rates. A combination of both measurement techniques is possible by the Cox-Merz-Relation. The detected differences in the rheological behavior of both charges are summarized in two material behavior describing model approaches and added to the simulation. In this paper the results of processing-simulations with standard filling parameters are presented with two ABS charges. Part quality defining quantities such as temperature, pressure and shear stress are investigated and the influence of charge variations is pointed out with respect to electro plating quality demands. Furthermore, the results of simulations with a new quality related process control are presented and compared to the standard processing.

  8. Variation of b and p values from aftershocks sequences along the Mexican subduction zone and their relation to plate characteristics

    NASA Astrophysics Data System (ADS)

    Ávila-Barrientos, L.; Zúñiga, F. R.; Rodríguez-Pérez, Q.; Guzmán-Speziale, M.

    2015-11-01

    Aftershock sequences along the Mexican subduction margin (between coordinates 110ºW and 91ºW) were analyzed by means of the p value from the Omori-Utsu relation and the b value from the Gutenberg-Richter relation. We focused on recent medium to large (Mw > 5.6) events considered susceptible of generating aftershock sequences suitable for analysis. The main goal was to try to find a possible correlation between aftershock parameters and plate characteristics, such as displacement rate, age and segmentation. The subduction regime of Mexico is one of the most active regions of the world with a high frequency of occurrence of medium to large events and plate characteristics change along the subduction margin. Previous studies have observed differences in seismic source characteristics at the subduction regime, which may indicate a difference in rheology and possible segmentation. The results of the analysis of the aftershock sequences indicate a slight tendency for p values to decrease from west to east with increasing of plate age although a statistical significance is undermined by the small number of aftershocks in the sequences, a particular feature distinctive of the region as compared to other world subduction regimes. The b values show an opposite, increasing trend towards the east even though the statistical significance is not enough to warrant the validation of such a trend. A linear regression between both parameters provides additional support for the inverse relation. Moreover, we calculated the seismic coupling coefficient, showing a direct relation with the p and b values. While we cannot undoubtedly confirm the hypothesis that aftershock generation depends on certain tectonic characteristics (age, thickness, temperature), our results do not reject it thus encouraging further study into this question.

  9. Phylogenetic relations of humans and African apes from DNA sequences in the Psi eta-globin region

    SciTech Connect

    Miyamoto, M.M.; Slightom, J.L.; Goodman, M.

    1987-10-16

    Sequences from the upstream and downstream flanking DNA regions of the Psi eta-globin locus in Pan troglodytes (common chimpanzee), Gorilla gorilla (gorilla), and Pongo pygmaeus (orangutan, the closest living relative to Homo, Pan, and Gorilla) provided further data for evaluating the phylogenetic relations of humans and African apes. These newly sequenced orthologs (an additional 4.9 kilobase pairs (kbp) for each species) were combined with published Psi eta-gene sequences and then compared to the same orthologous stretch (a continuous 7.1-kbp region) available for humans. Phylogenetic analysis of these nucleotide sequences by the parsimony method indicated (i) that human and chimpanzee are more closely related to each other than either is to gorilla and (ii) that the slowdown in the rate of sequence evolution evident in higher primates is especially pronounced in humans. These results indicate that features unique to African apes (but not to humans) are primitive and that even local molecular clocks should be applied with caution.

  10. Perceived HIV-related sexual risks and prevention practices of African American women in the southeastern United States.

    PubMed

    Timmons, S M; Sowell, R L

    1999-01-01

    African American women in the southeastern United States constitute the fastest growing segment of those infected with the human immunodeficiency virus (HIV). Little data exist about the relationships between HIV infection risks and preventive practices. In this article, we describe a focus group investigation of how HIV-related sexual risks are perceived by 19 heterosexual African American women, ages 18 to 44. Data were analyzed and interpreted using content analysis, where key ideas, words, and phrases were grouped based on their relation to the purpose of the study. Four themes were revealed: "a man will be a man," inconsistent and/or no condom use, safe relationships, and racism and discrimination. Perceived safety within relationships mediated both perceptions of HIV-related risks and sexual practices. In light of beliefs about the riskiness of sex with high-risk partners, fear of HIV, and the importance of self love in minimizing HIV infection risks, the women continued to practice unsafe sexual behaviors. Results indicate that women perceive themselves as victims in society and that this perception limits their propensity to take action to protect themselves from HIV. Successful HIV infection prevention interventions need to address negative social and economic factors that define the context of many women's lives. PMID:10889636

  11. Quality of life in patients with systemic lupus erythematosus (SLE) compared with related controls within a unique African American population

    PubMed Central

    Barnado, A; Wheless, L; Meyer, AK; Gilkeson, GS; Kamen, DL

    2012-01-01

    The patient’s perspective of how their health affects their function is health-related quality of life (HRQOL). HRQOL is poorer in patients with systemic lupus erythematosus (SLE). Few HRQOL studies in SLE patients have focused on African Americans despite an increased disease burden compared with Caucasians. The African American Gullah population of South Carolina has a homogeneous genetic and environmental background and a high prevalence of multi-patient families with SLE. Demographics, medical history, and Short-Form 36 (SF-36) were measured within a cohort of Gullah SLE cases and related controls. Compared with related controls (n = 37), cases (n = 89) had a lower Physical Component Summary (PCS, 41.8 vs. 52.3, p < 0.01), but not Mental Component Summary (MCS, 55.0 vs. 56.0, p = 0.70). The difference in PCS was no longer significant upon adjustment for working status, disability, and medical conditions. None of the 11 SLE American College of Rheumatology criteria, disease duration, or Systemic Lupus International Collaborating Clinics Damage Index were associated with either PCS or MCS. Cases and controls had similar MCS scores. We hypothesize that this lack of effect of SLE on MCS may be due to disease-coping mechanisms interplaying with cultural factors unique to the Gullah. PMID:22031537

  12. The Effect of Message Framing on African American Women's Intention to Participate in Health-Related Research.

    PubMed

    Balls-Berry, Joyce E; Hayes, Sharonne; Parker, Monica; Halyard, Michele; Enders, Felicity; Albertie, Monica; Pinn, Vivian; Radecki Breitkopf, Carmen

    2016-05-01

    This study examined the effect of message framing on African American women's intention to participate in health-related research and actual registration in ResearchMatch (RM), a disease-neutral, national volunteer research registry. A community-engaged approach was used involving collaboration between an academic medical center and a volunteer service organization formed by professional women of color. A self-administered survey that contained an embedded message framing manipulation was distributed to more than 2,000 African American women attending the 2012 national assembly of The Links, Incorporated. A total of 391 surveys were completed (381 after exclusion: 187 containing the gain-framed message and 194 containing the loss-framed message). The majority (57%) of women expressed favorable intentions to participate in health-related research, and 21% subsequently enrolled in RM. The effect of message framing on intention was moderated by self-efficacy. There was no effect of message framing on RM registration; however, those with high self-efficacy were more than 2 times as likely as those with low self-efficacy to register as a potential study volunteer in RM (odds ratio = 2.62, 95% confidence interval [1.29, 5.33]). This investigation makes theoretical and practical contributions to the field of health communication and informs future strategies to meaningfully and effectively include women and minorities in health-related research. PMID:27077665

  13. Topographic form of the Coast Ranges of the Cascadia Margin in relation ot coastal uplift rates and plate subduction

    NASA Technical Reports Server (NTRS)

    Kelsey, Harvey M.; Engebretson, David C.; Mitchell, Clifton E.; Ticknor, Robert L.

    1994-01-01

    The Coast Ranges of the Cascadia margin are overriding the subducted Juan de Fuca/Gorda plate. We investigate the extent to which the latitudinal change in attributes related to the subduction process. These attributes include the varibale age of the subducted slab that underlies the Coast Ranges and average vertical crustal velocities of the western margin of the Coast Rnages for two markedly different time periods, the last 45 years and the last 100 kyr. These vertical crustal velocities are computed from the resurveying of highway bech marks and from the present elevation of shore platforms that have been uplifted in the late Quaternary, respectively. Topogarphy of the Coast Ranges is in part a function of the age and bouyancy of the underlying subducted plate. This is evident in the fact that the two highest topographic elements of the Coast Rnages, the Klamath Mountains and the Olympic Mountains, are underlain by youngest subducted oceanic crust. The subducted Blanco Fracture Zone in southernmost Oregon is responsible for an age discontinuity of subducted crust under the Klamath Mountains. The norhtern terminus of hte topographically higher Klamaths is offset to the north relative to the position of the underlying Blanco Fracture Zone, teh offset being in the direction of migration of the farcture zone, as dictated by relative plate motions. Vertical crustal velocities at the coast, derived from becnh mark surveys, are as much as an order of magnitude greater than vertical crustal velocities derived from uplifted shore platforms. This uplift rate discrepancy indicates that strain is accumulating on the plate margin, to be released during the next interplate earthquake. In a latitudinal sense, average Coast Rnage topography is relatively high where bench mark-derived, short-term vertical crustal velocities are highest. Becuase the shore platform vertical crustal velocities reflect longer-term, premanent uplift, we infer that a small percentage of the

  14. Topographic form of the Coast Ranges of the Cascadia Margin in relation ot coastal uplift rates and plate subduction

    NASA Astrophysics Data System (ADS)

    Kelsey, Harvey M.; Engebretson, David C.; Mitchell, Clifton E.; Ticknor, Robert L.

    1994-06-01

    The Coast Ranges of the Cascadia margin are overriding the subducted Juan de Fuca/Gorda plate. We investigate the extent to which the latitudinal change in attributes related to the subduction process. These attributes include the varibale age of the subducted slab that underlies the Coast Ranges and average vertical crustal velocities of the western margin of the Coast Rnages for two markedly different time periods, the last 45 years and the last 100 kyr. These vertical crustal velocities are computed from the resurveying of highway bech marks and from the present elevation of shore platforms that have been uplifted in the late Quaternary, respectively. Topogarphy of the Coast Ranges is in part a function of the age and bouyancy of the underlying subducted plate. This is evident in the fact that the two highest topographic elements of the Coast Rnages, the Klamath Mountains and the Olympic Mountains, are underlain by youngest subducted oceanic crust. The subducted Blanco Fracture Zone in southernmost Oregon is responsible for an age discontinuity of subducted crust under the Klamath Mountains. The norhtern terminus of hte topographically higher Klamaths is offset to the north relative to the position of the underlying Blanco Fracture Zone, teh offset being in the direction of migration of the farcture zone, as dictated by relative plate motions. Vertical crustal velocities at the coast, derived from becnh mark surveys, are as much as an order of magnitude greater than vertical crustal velocities derived from uplifted shore platforms. This uplift rate discrepancy indicates that strain is accumulating on the plate margin, to be released during the next interplate earthquake. In a latitudinal sense, average Coast Rnage topography is relatively high where bench mark-derived, short-term vertical crustal velocities are highest. Becuase the shore platform vertical crustal velocities reflect longer-term, premanent uplift, we infer that a small percentage of the

  15. Propagation of SH waves in a piezoelectric/piezomagnetic plate: Effects of interfacial imperfection couplings and the related physical mechanisms

    NASA Astrophysics Data System (ADS)

    Wei, Hong-Xing; Li, Yong-Dong; Xiong, Tao; Guan, Yong

    2016-09-01

    The problem of dispersive SH wave in a piezoelectric/piezomagnetic plate that contains an imperfect interface is considered in the present work. An imperfection coupling model is adopted to describe the magnetic, electric and mechanical imperfections on the interface. A transcendental dispersion equation is derived and numerically solved to get the phase velocity. The validity of the numerical procedure is verified in a degenerated case. The effects of the coupled interfacial imperfections on the dispersion behavior of SH waves are discussed in detail and the related underlying physical mechanisms are explained.

  16. AIDS-Related Stigmas and Safe-Sex Practices of African-American College Students: A Pilot Study.

    ERIC Educational Resources Information Center

    Chandler, Donald S., Jr.

    This study examined the safe-sex practices of African-American colleges students in light of culturally-specific beliefs that stigmatize Acquired Immune Deficiency Syndrome (AIDS) in the African-American community. A total of 21 self-selected, sexually-active African-American students (15 females and 6 males) aged 18-22 completed the AIDS…

  17. African-American Male Student Perceptions about Factors Related to Why Black Boys Drop out of Secondary School

    ERIC Educational Resources Information Center

    Edwards, Anntwanique DeVonne

    2012-01-01

    African-American males are overwhelmingly represented in the nation's dropout rates. Dropping out of school has serious social and economic consequences for our society. The dropout rate is overwhelmingly represented by African-American male students, but limited attention is given to student voice. This study examines African-American male…

  18. The Cultural Relevance of Mindfulness Meditation as a Health Intervention for African Americans: Implications for Reducing Stress-Related Health Disparities.

    PubMed

    Woods-Giscombé, Cheryl L; Gaylord, Susan A

    2014-09-01

    African Americans experience a disproportionate rate of stress-related health conditions compared to European Americans. Mindfulness meditation has been shown to be effective for managing stress and various stress-related health conditions. This study explored the cultural relevance of mindfulness meditation training for African Americans adults. Fifteen African American adults with past or current experience with mindfulness meditation training were interviewed. Participants felt that mindfulness meditation helped them with enhanced stress management, direct health improvement, and enhanced self-awareness and purposefulness. They felt that they would recommend it and that other African Americans would be open to the practice but suggested that its presentation may need to be adapted. They suggested emphasizing the health benefits, connecting it to familiar spiritual ideology and cultural practices, supplementing the reading material with African American writers, increasing communication (education, instructor availability, "buddy system," etc.), and including African Americans as instructors and participants. By implementing minor adaptations that enhance cultural relevance, mindfulness meditation can be a beneficial therapeutic intervention for this population. PMID:24442592

  19. The burden of natural and technological disaster-related mortality on gross domestic product (GDP) in the WHO African region.

    PubMed

    Kirigia, Joses M; Sambo, Luis G; Aldis, W; Mwabu, Germano M

    2002-01-01

    The WHO Africa region has the highest disaster mortality rate compared to the other five regions of the organization. Those deaths are hypothesized to have significantly negative effect on per capita gross domestic product (GDP). The objective of this study was to estimate the loss in GDP attributable to natural and technological disaster-related mortality in the WHO African Region. We estimated the impact of disaster-related mortality on GDP using double-log econometric model and cross-sectional data (from the UNDP and the World Bank publications) on 45 out of 46 countries in the WHO African Region. The coefficients for capital (K), educational enrolment (EN), life expectancy (LE) and exports (X) had a positive sign; while imports (M) and disaster mortality (DS) were found to impact negatively on GDP. The abovementioned explanatory variables were found to have statistically significant effect on GDP at 5% level in a t-distribution test. Disaster mortality of a single person was found to reduce GDP by US$0.018. We have demonstrated that disaster mortality has a significant negative effect on GDP. Thus, as policy-makers strive to increase GDP through capital investment, export promotion and increase in educational enrolment, they should always recall that investments in strengthening national capacity to mitigate the effects of national disasters expeditiously and effectively shall yield significant economic returns. PMID:17298162

  20. Negative and positive peer influence: Relations to positive and negative behaviors for African American, European American, and Hispanic adolescents.

    PubMed

    Padilla-Walker, Laura M; Bean, Roy A

    2009-04-01

    The purpose of the current study was to examine adolescents' perceptions of negative and positive peer influence (i.e., indirect peer association and direct peer pressure) as they related to adolescent behavior. Regression analyses were conducted using a sample of African American, European American, and Hispanic adolescents (N=1659, M age=16.06, SD=1.10). The study found differences and similarities in relation to respondents' ethnicity vis-à-vis indirect peer association and adolescent behavior. Although few ethnic-based differences occurred as a function of indirect negative peer association, indirect positive peer association was not as consistently or as strongly related to behaviors for minority youth as it was for European American youth. PMID:18703225

  1. Multiple mantle upwellings beneath the Northern East-African Rift System from relative P- and S-wave traveltime tomography

    NASA Astrophysics Data System (ADS)

    Civiero, Chiara; Hammond, James; Goes, Saskia; Fishwick, Stewart; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, Mike; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rumpker, Georg; Stuart, Graham

    2015-04-01

    Mantle plumes have been invoked as the likely cause of East African Rift volcanism and extension. However, the nature of mantle upwelling is debated, with proposed configurations ranging from a single broad plume, the African Superplume, connected to the LLSVP beneath Southern Africa, to one or more distinct lower-mantle sources along the rift. We present a new relative travel-time tomography model that images detailed P- and S- wave velocities from P,S and SKS phases below the northern East-African, Red Sea and Gulf of Aden rift. Data comes from stations that cover the area from Tanzania to Saudi Arabia. The aperture of the integrated dataset allows us to image for the first time structures of ~100 km length scale down to depths of 900 km beneath this region. Our images provide evidence of at least two low-velocity structures with a diameter of ~200 km that continue through the transition zone and into the lower mantle: the first extends to at least 900 km beneath Afar, and a second reaching at least 750 km depth just west of the Main Ethiopian Rift, a region with off-rift volcanism. Taking into account seismic sensitivity to temperature and thermally controlled phase boundary topography, we interpret these features as multiple focused upwellings from below the transition zone with excess temperatures of 100±50 K. The scale of the upwellings is smaller than any of the previously proposed lower mantle plume sources. This suggests the ponding or flow of deep-plume material below the transition zone may be spawning smaller upper-mantle upwellings.

  2. Evaluation of Relative Sensitivity of SAW and Flexural Plate Wave Devices for Atmospheric Sensing

    NASA Technical Reports Server (NTRS)

    White, Richard M.; Black, Justin; Chen, Bryan

    1998-01-01

    The objective of this project is to evaluate the suitability of the ultrasonic flexural plate wave (FPW) device as the detector in a gas chromatograph (GC). Of particular interest is the detection of nitrous oxide (N2O). From experimental results we conclude analyte detection is achieved through two mechanisms: changes in gas density, and mass loading of the device membrane due to the sorption of gas molecules. Reducing the dead volume of the FPW chamber increased the FPW response. A comparison of the FPW response to that of the surface acoustic wave (SAW) detector provided with the GC (made by MSI, Microsensor Technologies, Inc.), shows that for unseparated N2O in N2, the FPW exhibits a sensitivity that is at least 550 times greater than that of the SAW device. A Porapak Q column was found to separate N2O from its carrier gas, N2 or He. With the Porapak Q column, a coated FPW detected 1 ppm N2O in N2 or He, with a response magnitude of 7 Hz. A coated SAW exhibited a response of 25 Hz to pure N2O. The minimal detectable N2O concentrations of the sensors were not evaluated.

  3. "She Told Them, Oh That Bitch Got AIDS": Experiences of Multilevel HIV/AIDS-Related Stigma Among African American Women Living with HIV/AIDS in the South.

    PubMed

    Fletcher, Faith; Ingram, Lucy Annang; Kerr, Jelani; Buchberg, Meredith; Bogdan-Lovis, Libby; Philpott-Jones, Sean

    2016-07-01

    African American women bear a disproportionate burden of HIV/AIDS in the United States. Although they constitute only 13% of the US population, African Americans account for nearly 65% of all new HIV infections among American women. In addition, this population suffers comparatively greater adverse health outcomes related to HIV status. African American women living with HIV in the South may be further burdened by HIV/AIDS stigma, which is comparatively more pronounced in this region. To further explore this burden, we used narrative data and the Social Ecological Model to explore how African American women living with HIV in the US South recount, conceptualize, and cope with HIV/AIDS stigma at interpersonal, community, and institutional levels. Our narrative analysis suggests that HIV-positive African American women living in the South are vulnerable to experiences of multilevel HIV stigma in various settings and contexts across multiple domains of life. Stigma subsequently complicated disclosure decisions and made it difficult for women to feel supported in particular social, professional and medical settings that are generally regarded as safe spaces for noninfected individuals. Findings suggest that the debilitating and compounded effect of multilevel HIV/AIDS stigma on HIV-positive African American women in the South warrants closer examination to tailor approaches that effectively address the unique needs of this population. PMID:27410498

  4. Iberian plate kinematics: A jumping plate boundary between Eurasia and Africa

    USGS Publications Warehouse

    Srivastava, S.P.; Schouten, Hans; Roest, W.R.; Klitgord, Kim D.; Kovacs, L.C.; Verhoef, J.; Macnab, R.

    1990-01-01

    THE rotation of Iberia and its relation to the formation of the Pyrenees has been difficult to decipher because of the lack of detailed sea-floor spreading data, although several models have been proposed1-7. Here we use detailed aeromagnetic measurements from the sea floor offshore of the Grand Banks of Newfoundland to show that Iberia moved as part of the African plate from late Cretaceous to mid-Eocene time, with a plate boundary extending westward from the Bay of Biscay. When motion along this boundary ceased, a boundary linking extension in the King's Trough to compression along the Pyrenees came into existence. Finally, since the late Oligocene, Iberia has been part of the Eurasian plate, with the boundary between Eurasia and Africa situated along the Azores-Gibraltar fracture zone.

  5. Genetic variations in vitamin D-related pathways and breast cancer risk in African American women in the AMBER consortium.

    PubMed

    Yao, Song; Haddad, Stephen A; Hu, Qiang; Liu, Song; Lunetta, Kathryn L; Ruiz-Narvaez, Edward A; Hong, Chi-Chen; Zhu, Qianqian; Sucheston-Campbell, Lara; Cheng, Ting-Yuan David; Bensen, Jeannette T; Johnson, Candace S; Trump, Donald L; Haiman, Christopher A; Olshan, Andrew F; Palmer, Julie R; Ambrosone, Christine B

    2016-05-01

    Studies of genetic variations in vitamin D-related pathways and breast cancer risk have been conducted mostly in populations of European ancestry, and only sparsely in African Americans (AA), who are known for a high prevalence of vitamin D deficiency. We analyzed 24,445 germline variants in 63 genes from vitamin D-related pathways in the African American Breast Cancer Epidemiology and Risk (AMBER) consortium, including 3,663 breast cancer cases and 4,687 controls. Odds ratios (OR) were derived from logistic regression models for overall breast cancer, by estrogen receptor (ER) status (1,983 ER positive and 1,098 ER negative), and for case-only analyses of ER status. None of the three vitamin D-related pathways were associated with breast cancer risk overall or by ER status. Gene-level analyses identified associations with risk for several genes at a nominal p ≤ 0.05, particularly for ER- breast cancer, including rs4647707 in DDB2. In case-only analyses, vitamin D metabolism and signaling pathways were associated with ER- cancer (pathway-level p = 0.02), driven by a single gene CASR (gene-level p = 0.001). The top SNP in CASR was rs112594756 (p = 7 × 10(-5), gene-wide corrected p = 0.01), followed by a second signal from a nearby SNP rs6799828 (p = 1 × 10(-4), corrected p = 0.03). In summary, several variants in vitamin D pathways were associated with breast cancer risk in AA women. In addition, CASR may be related to tumor ER status, supporting a role of vitamin D or calcium in modifying breast cancer phenotypes. PMID:26650177

  6. Violence exposure and health related risk among African American adolescent female detainees: A strategy for reducing recidivism

    PubMed Central

    Woodson, Kamilah M.; Hives, Courtney; Sanders-Phillips, Kathy

    2010-01-01

    Juvenile crime and violent victimization continue to be significant social problems (Fitzpatrick, Piko, Wright, & LaGory, 2005); in that, adolescents, females in particular, are likely to participate in health related risk behaviors as result of having been victimized or exposed to a violent environment. Specifically, abuse, neglect, sexual molestation, poverty, and witnessing violence are well known risk factors for the development of trauma-related psychopathology and poor outcomes relative to delinquency, drug and alcohol abuse, and HIV risk behaviors (Steiner, Garcia, & Matthews, 1997). HIV infection is a common public health concern disproportionally affecting adolescent African American female detainees. This unique population has a serious history of violence exposure, which subsequently tends to lead to engaging in risky sexual behaviors, mental health problems, and abusing substances. Also, as a result of little to no intervention, this population is recidivating at an alarming rate, a problem that may further exacerbate the expression of health-related risk behaviors among African American adolescent female detainees. The authors briefly describe a pilot program to be implemented in the juvenile justice system that is based on the Model of Accumulated Risk (Garbarino, 1996), Bronfenbrenner’s Ecological Model (1994), and the Positive Youth Justice Model (Butts, Bazemore, & Meroe, 2009). The program proposes to reduce risky sexual behaviors, teach alternatives to abusing substances, treat mental health concerns, and reduce the rate of recidivism through “positive youth development”, PYD (Butts, Bazemore, & Meroe, 2009). Tying elements of wraparound services and reeducation together, this program addresses salient concerns that may have an impact on an adolescent detainees’ success following their release from prison in a holistic manner. PMID:21373205

  7. An Initial Evaluation of a Culturally-Adapted Social Problem Solving and Relational Aggression Prevention Program for Urban African American Relationally Aggressive Girls

    PubMed Central

    Leff, Stephen S.; Gullan, Rebecca Lakin; Paskewich, Brooke S.; Abdul-Kabir, Saburah; Jawad, Abbas F.; Grossman, Michael; Munro, Melissa A.; Power, Thomas J.

    2010-01-01

    Recent research demonstrating that relational aggression is associated with peer relationship difficulties, internalizing and externalizing behaviors, social processing deficits, and possibly later mental health disorders among girls has emphasized the need to address the unique expression of aggression amongst females. Despite these findings, almost all aggression interventions have been directed towards physically aggressive boys. In the current manuscript, authors describe the acceptability and initial effectiveness of a culturally-adapted social problem solving/social skills intervention for inner-city third to fifth grade urban, African American, relationally aggressive girls called the Friend to Friend Program. The authors partnered with youth, teachers, parents, and playground supervisors to design the program, and the current study presents preliminary data suggesting that the intervention is viewed as highly acceptable by participating girls and teachers. Further, the intervention appears to have promise for decreasing at-risk girls’ levels of relationally and physically aggressive behaviors, hostile attributions, and loneliness. PMID:19830622

  8. Racial and Ethnic-Related Stressors as Predictors of Perceived Stress and Academic Performance for African American Students at a Historically Black College and University

    ERIC Educational Resources Information Center

    Greer, Tawanda M.

    2008-01-01

    The purpose of this investigation was to determine whether racial and ethnic-related stressors were associated with overall levels of perceived stress and academic performance among African American students at a historically Black college and university (HBCU). Hierarchical regression analyses were used to test racial and ethnic-related stressors…

  9. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence. PMID:17799689

  10. West African monsoon decadal variability and surface-related forcings: second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II)

    NASA Astrophysics Data System (ADS)

    Xue, Yongkang; De Sales, Fernando; Lau, William K.-M.; Boone, Aaron; Kim, Kyu-Myong; Mechoso, Carlos R.; Wang, Guiling; Kucharski, Fred; Schiro, Kathleen; Hosaka, Masahiro; Li, Suosuo; Druyan, Leonard M.; Sanda, Ibrah Seidou; Thiaw, Wassila; Zeng, Ning; Comer, Ruth E.; Lim, Young-Kwon; Mahanama, Sarith; Song, Guoqiong; Gu, Yu; Hagos, Samson M.; Chin, Mian; Schubert, Siegfried; Dirmeyer, Paul; Ruby Leung, L.; Kalnay, Eugenia; Kitoh, Akio; Lu, Cheng-Hsuan; Mahowald, Natalie M.; Zhang, Zhengqiu

    2016-06-01

    The second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II) is designed to improve understanding of the possible roles and feedbacks of sea surface temperature (SST), land use land cover change (LULCC), and aerosols forcings in the Sahel climate system at seasonal to decadal scales. The project's strategy is to apply prescribed observationally based anomaly forcing, i.e., "idealized but realistic" forcing, in simulations by climate models. The goal is to assess these forcings' effects in producing/amplifying seasonal and decadal climate variability in the Sahel between the 1950s and the 1980s, which is selected to characterize the great drought period of the last century. This is the first multi-model experiment specifically designed to simultaneously evaluate such relative contributions. The WAMME II models have consistently demonstrated that SST forcing is a major contributor to the twentieth century Sahel drought. Under the influence of the maximum possible SST forcing, the ensemble mean of WAMME II models can produce up to 60 % of the precipitation difference during the period. The present paper also addresses the role of SSTs in triggering and maintaining the Sahel drought. In this regard, the consensus of WAMME II models is that both Indian and Pacific Ocean SSTs greatly contributed to the drought, with the former producing an anomalous displacement of the Intertropical Convergence Zone before the WAM onset, and the latter mainly contributes to the summer WAM drought. The WAMME II models also show that the impact of LULCC forcing on the Sahel climate system is weaker than that of SST forcing, but still of first order magnitude. According to the results, under LULCC forcing the ensemble mean of WAMME II models can produces about 40 % of the precipitation difference between the 1980s and the 1950s. The role of land surface processes in responding to and amplifying the drought is also identified. The results suggest that catastrophic

  11. Movements and corridors of African elephants in relation to protected areas

    NASA Astrophysics Data System (ADS)

    Douglas-Hamilton, I.; Krink, T.; Vollrath, F.

    2005-04-01

    Understanding how mammals satisfy their need for space in fragmenting ecosystems is crucial for ecosystem conservation. Using state-of-the-art global positioning system (GPS) technology we tracked 11 focal African elephants (Loxodonta africana) in Kenya at 3-hourly fix intervals and collected between 34 and 406 days per individual. Our recordings gave a high spatio-temporal resolution compared to previous studies and allowed novel insights into range use. The actual ranges of the tracked elephants are smaller than usually represented. Moreover, the ranges in our sample were complex and not confined to officially designated protected areas, except where fenced. All the unfenced elephants in our sample had distinct `home sectors' linked by `travel' corridors. Within each home sector the elephants concentrated in favourite `core zones'. Such core zones tended to lie in protected areas whereas corridors typically crossed unprotected range. Elephants moved significantly faster along corridors than elsewhere in their range, which suggests awareness of danger outside the protected area. We conclude that understanding the complex use of an animal's range is crucial for conservation planning aiming to balance animal interests with those of human beings that co-habit in their range.

  12. Plant mineral concentrations related to foraging preferences of western lowland gorilla in Central African forest clearings.

    PubMed

    Metsio Sienne, Julia; Buchwald, Rainer; Wittemyer, George

    2014-12-01

    In the Central African rain forest, mineral resources essential to organisms are distributed heterogeneously. Forest clearings, locally known as bais, attract numerous species presumably due to the mineral richness of these sites, though understanding of the factors drawing species to bais remains speculative. Western lowland gorillas (Gorilla g. gorilla) selectively feed on particular plant species and parts within bais, but studies of such feeding preferences have focused on one site. Here, we compared concentrations of minerals and macronutrients from plants gorillas consumed and those they did not in 16 bais to gain inference regarding drivers of resource selection within bais and bai use. The availability of gorilla feeding plants varied between surveyed bais, with some consumed species occurring only at a few bais. Regardless of bai specific species composition, significantly higher concentrations of Na, K, and Ca were found in consumed plants, and other trace minerals were more common in consumed plants. In contrast, macronutrients appeared to play no major role in feeding plant selectivity with consumed species often having lower concentrations than non-consumed species. We found evidence for seasonal differences in Mg and Na concentrations, but the concentrations of other minerals in consumed plants were consistent across time. These findings provide insight to the drivers of bai visitation by gorillas. The high variation in species across bais may elicit use of multiple bais, but the general increased mineral composition of consumed species across bais suggests metabolic requirements may be met through consumption of a variety of species. PMID:24865332

  13. Marginal deformation of crustal plates as key to crustal motion, crustal spirals, and the driving force

    SciTech Connect

    Wood, B.G.M.

    1986-07-01

    Present plate tectonic models concentrate on compressive- and extensive-type plate margins, often incorporating shear margins as a subtype of compressive margins. However, if a single moving plate is considered, it becomes apparent that the leading edge is a compressive margin, the trailing edge is an extensive margin, and the lateral edges are shear margins. Conversely, if a plate's margin can be recognized by identifying areas of subduction (compression), rifting (extension), and strike slip and buckle folding (shearing), then not only can a plate be identified but its motion can also be inferred. The Pacific plate provides an excellent example. It is bounded by subduction trenches along its west-northwest margin, extension rifts along its east-southeast margin, and shear and buckle-fold complexes along its south-southwest and north-northeast margins. A west-northwest motion is inferred. As other major plates are examined, two striking features are revealed. A west-northwest to northwest motion is consistently identified, and the plates line up end to end forming a northwest-spiraling segmented band encircling the globe. The lateral margins of this band form the well-known Tethyan shear system. The plates comprising this band are of varying sizes and composition, and the extent of deformation along a plate margin is directly related to plate size. The Pacific and Eurasian plates dominate in size and marginal deformation. The tail of this north-spiraling ribbon of crustal plates is deformed in the Southern Hemisphere, most notably in the area of the African, Indian, and Australian plates. Each southern plate has a strong north component of motion as well as a counterclockwise spiraling action. The plates appear to have rotated in response to drag along the southern margin of the Pacific and Eurasian plates.

  14. The psychosocial adjustment of African American youth from single mother homes: the relative contribution of parents and peers.

    PubMed

    Chester, Charlene; Jones, Deborah J; Zalot, Alecia; Sterrett, Emma

    2007-01-01

    This study examined the relative roles of parents and peers in the psychosocial adjustment of African American youth (7-15 years old) from single mother homes (N = 242). Main effects of both positive parenting and peer relationship quality were found for youth depressive symptoms. In addition, a main effect of peer relationship quality and an interaction of Positive Parenting x Peer Relationship Quality emerged for youth externalizing symptoms. When mothers engaged in higher levels of positive parenting behavior, peer relationship quality was not associated with youth externalizing symptomatology. When mothers engaged in lower levels of positive parenting behavior, however, higher peer relationship quality was associated with greater youth externalizing symptomatology. Clinical implications and future research directions are discussed. PMID:17658980

  15. Jurassic silicic volcanism in the Transantarctic Mountains: Was it related to plate margin processes or to Ferrar magmatism?

    USGS Publications Warehouse

    Elliot, D.H.; Fleming, T.H.; Foland, K.A.; Fanning, C.M.

    2007-01-01

    Silicic volcanism in the Transantarctic Mountains, represented by rhyolitic tuff that mainly precedes emplacement of the Ferrar Large Igneous Province, is important in interpretation of the tectonic evolution of the Antarctic sector of Gondwana. Sr and Nd isotope data indicate that the tuffs are not directly related to Ferrar magmatism nor to melting of the underlying Ross orogen crust yet zircon gives a U-Pb age of 182.7±1.8 Ma, similar to the U/Pb age for the Ferrar. Distribution of the silicic tuffs along 1400 km of the Transantarctic Mountains suggests, alternatively, a relationship to the Gondwana plate margin. Although West Antarctica comprises Mesoproterozoic crustal terrains, few analyzed rocks are compatible isotopically with the Lower Jurassic tuffs. The source of the tuffs must lie in unexposed Early Jurassic magmatic centers in West Antarctica or an unexposed crustal terrain beneath the Transantarctic Mountains.

  16. Routine removal of the plate after surgical treatment for mandibular angle fracture with a third molar in relation to the fracture line

    PubMed Central

    Yamamoto, Kazuhiko; Matsusue, Yumiko; Horita, Satoshi; Murakami, Kazuhiro; Sugiura, Tsutomu; Kirita, Tadaaki

    2015-01-01

    Purpose: The purpose was to analyze the clinical course of surgically treated mandibular angle fractures from the viewpoint of routine removal of the plate because these fractures are associated with high rates of complications and plate removal. Subjects and Methods: The subjects were 40 patients with unilateral mandibular angle fracture, which was intraorally reduced and principally fixed with a single miniplate on the external oblique ridge. The third molar in relation to the fracture line was extracted in seven patients during the surgery. Clinical course was evaluated in terms of removal of the plate, preservation of the third molar and complications. Results: One patient showed a wound infection postoperatively, and two patients developed pericoronitis during the follow-up. These were managed with medication and local irrigation. One patient with a preserved third molar did not make a required visit and was lost from the follow-up. Removal of the plates was performed in 39 patients after confirmation of good fracture healing, mostly within a year. Twenty-four of 32 preserved third molars were simultaneously extracted. These procedures were generally performed under local anesthesia on an outpatient basis, and they did not cause any complications. Conclusions: Routine removal of the plate after surgical treatment for mandibular angle fractures, simultaneously with extraction of the third molar if indicated, may be beneficial to avoid complications related to the plate and the third molar later in life. PMID:26389039

  17. Relative impacts of insolation changes, meltwater fluxes and ice sheets on African and Asian monsoons during the Holocene

    NASA Astrophysics Data System (ADS)

    Marzin, Charline; Braconnot, Pascale; Kageyama, Masa

    2013-11-01

    In order to better understand the evolution of the Afro-Asian monsoon in the early Holocene, we investigate the impact on boreal summer monsoon characteristics of (1) a freshwater flux in the North Atlantic from the surrounding melting ice sheets and (2) a remnant ice sheet over North America and Europe. Sensitivity experiments run with the IPSL_CM4 model show that both the meltwater flux and the remnant ice sheets induce a cooling of similar amplitude of the North Atlantic leading to a southward shift of the Inter-Tropical Convergence Zone over the tropical Atlantic and to a reduction of the African monsoon. The two perturbations have different impacts in the Asian sector. The meltwater flux results in a weakening of the Indian monsoon and no change in the East Asian monsoon, whereas the remnant ice sheets induce a strengthening of the Indian monsoon and a strong weakening of the East Asian monsoon. Despite the similar coolings in the Atlantic Ocean, the ocean heat transport is reduced only in the meltwater flux experiment, which induces slight differences between the two experiments in the role of the surface latent heat flux in the tropical energetics. In the meltwater experiment, the southward shift of the subtropical jet acts to cool the upper atmosphere over the Tibetan Plateau and hence to weaken the Indian monsoon. In the ice sheet experiment this effect is overwhelmed by the changes in extratropical stationary waves induced by the ice sheets, which are associated with a larger cooling over the Eurasian continent than in the meltwater experiment. However these sensitivity experiments suggest that insolation is the dominant factor explaining the relative changes of the African, Indian and East Asian monsoons from the early to the mid-Holocene.

  18. Ethnic Differences in Profiles of Mother–Child Interactions and Relations to Emerging School Readiness in African American and Latin American Children

    PubMed Central

    Dyer, Nazly; Owen, Margaret Tresch; Caughy, Margaret O’Brien

    2015-01-01

    SYNOPSIS Objective This article examines ethnic similarities and differences in profiles of mother–child interaction qualities for low-income African American and Latin American mothers and associations with preschoolers’ emerging school readiness. Design Videotaped mother–child interactions were collected at age 2.5 years from a sample of African American (n = 192) and Latin American (n = 210) families. Profiles of maternal behavior were identified in person-centered within-group analyses of five ratings of maternal behavior from the videotaped interactions. Mothering profile groups were examined for relations to child receptive language, behavior problems, and pre-academic school readiness measured at age 3.5 years. Results Latent class analyses yielded three similar profiles in the two ethnicities identified as Child-Oriented, Directive, and Harsh-Intrusive mothering, and a fourth profile of Withdrawn mothering only among the African American mothers. For African American children, Child-Oriented and Directive mothering were each associated with higher pre-academic school readiness and language scores than Harsh-Intrusive or Withdrawn mothering. For Latin American children, Child-Oriented mothering was associated with fewer child behavior problems than Harsh-Intrusive mothering, and higher school readiness scores than Directive mothering. Conclusions Both similarities and differences were found between African American and Latin American families in observation- based mothering profiles and their linkages with preschoolers’ school readiness. PMID:26120285

  19. Is there a legacy of the U.S. Public Health Syphilis Study at Tuskegee in HIV/AIDS-related beliefs among heterosexual African-Americans and Latinos?

    PubMed

    Mays, Vickie M; Coles, Courtney N; Cochran, Susan D

    2012-01-01

    Knowledge of the US Public Health Syphilis Study at Tuskegee is sometime cited as a principal reason for the relatively low participation rates seen among racial/ethnic minorities, particularly African Americans, in biomedical research. However, only a few studies have actually explored this possibility. We use data from a random digit dial telephone survey of 510 African-Americans and 253 Latinos, age 18 to 45 years, to investigate associations between knowledge of the USPHS Syphilis Study at Tuskegee and endorsement of HIV/AIDS conspiracy theories. All respondents were drawn from an area of low-income, predominantly race-segregated inner city households in Los Angeles. Results indicate that African Americans were significantly more likely than Latinos to endorse HIV/AIDS conspiracy theories. Further, African Americans were more aware of the USPHS Syphilis Study at Tuskegee (SST). Nevertheless, 72% of African Americans and 94% of Latinos reported that they have never heard of the Syphilis Study at Tuskegee. Further, while awareness of the Syphilis Study at Tuskegee was a significant predictor of endorsing HIV/AIDS conspiracy theories, results suggest that other factors may be more important in accounting for low biomedical and behavioral study participation rates. PMID:23308036

  20. Attitudes and beliefs regarding depression, HIV/AIDS and HIV risk-related sexual behaviors among clinically depressed African American adolescent females

    PubMed Central

    Brawner, Bridgette M.

    2012-01-01

    Individuals’ attitudes and beliefs toward behaviors are key indicators of behavioral performance. The purpose of this study was to elucidate attitudes and beliefs about depression, HIV/AIDS and HIV risk-related sexual behaviors among clinically depressed African American adolescent females and to develop an understanding of their context for HIV risk. For this descriptive qualitative inquiry, semi-structured interviews and surveys were employed (N = 24). The narratives reveal that behavioral sequelae of depression (i.e. loneliness) can produce risk for HIV. These findings may guide psychiatric nurse educators, scientists, and practitioners to modify HIV risk among clinically depressed African American adolescent females. PMID:23164403

  1. Attitudes and beliefs regarding depression, HIV/AIDS, and HIV risk-related sexual behaviors among clinically depressed African American adolescent females.

    PubMed

    Brawner, Bridgette M

    2012-12-01

    Individuals' attitudes and beliefs toward behaviors are key indicators of behavioral performance. The purposes of this study were to elucidate attitudes and beliefs about depression, HIV/AIDS, and HIV risk-related sexual behaviors among clinically depressed African American adolescent females and to develop an understanding of their context for HIV risk. For this descriptive qualitative inquiry, semistructured interviews and surveys were employed (N = 24). The narratives reveal that behavioral sequelae of depression (i.e., loneliness) can produce risk for HIV. These findings may guide psychiatric nurse educators, scientists, and practitioners to modify HIV risk among clinically depressed African American adolescent females. PMID:23164403

  2. The Experience of African Students Studying Nursing in the United States in Relation to Their Use of Critical Thinking

    ERIC Educational Resources Information Center

    Tyson, Donald Lee

    2012-01-01

    This qualitative study explores the critical thinking experiences of African nursing students enrolled in several universities in the U.S. Using a semi-structured interview approach, twelve African students discussed their experiences using and learning a western critical thinking approach, as well as described their educational experiences in…

  3. Saying Grace: Praying over the Loss of African-American Religious and Food Culture (and How They Are Related)

    ERIC Educational Resources Information Center

    Hinton, Mary

    2008-01-01

    This article investigates the joint losses of food and religious culture in the African-American community, which has had a significant impact on the African-American community. Beginning with a historical perspective on the role of food in both a religious and cultural context, the article offers an analysis of why the dual losses have occurred,…

  4. European American and African American Mothers’ Emotion Socialization Practices Relate Differently to their Children’s Academic and Social-Emotional Competence

    PubMed Central

    Nelson, Jackie A.; Leerkes, Esther M.; Perry, Nicole B.; O’Brien, Marion; Calkins, Susan D.; Marcovitch, Stuart

    2012-01-01

    The current study examines whether the relation between mothers’ responses to their children’s negative emotions and teachers’ reports of children’s academic performance and social-emotional competence are similar or different for European American and African American families. Two hundred mothers (137 European American, 63 African American) reported on their responses to their 5-year-old children’s negative emotions and 150 kindergarten teachers reported on these children’s current academic standing and skillfulness with peers. Problem-focused responses to children’s negative emotions, which have traditionally been considered a supportive response, were positively associated with children’s school competence for European American children, but expressive encouragement, another response considered supportive, was negatively associated with children’s competence for African American children. The findings highlight the need to examine parental socialization practices from a culturally-specific lens. PMID:23914076

  5. Cultural, Sociofamilial, and Psychological Resources that Inhibit Psychological Distress in African Americans Exposed to Stressful Life Events and Race-Related Stress

    ERIC Educational Resources Information Center

    Utsey, Shawn O.; Giesbrecht, Norman; Hook, Joshua; Stanard, Pia M.

    2008-01-01

    This study tested a sociocultural model of stress and coping in a sample of 215 African Americans. Psychological resources (optimism, ego resilience) were modeled as a "nested self" (S. E. Hobfoll, 2001), supported by social resources (family adaptability and cohesion) and cultural resources (racial pride, religiosity). Race-related stress was a…

  6. Age-Related Patterns in Social Networks among European Americans and African Americans: Implications for Socioemotional Selectivity across the Life Span.

    ERIC Educational Resources Information Center

    Fung, Helene H.; Carstensen, Laura L.; Lang, Frieder, R.

    2001-01-01

    Tests socioemotional selectivity theory among African Americans and European Americans. Older people reported as many close partners but fewer peripheral partners as their younger counterparts, thus confirming the theory. A greater percentage of close social partners in social networks related to lower levels of happiness among the young age group…

  7. European-American and African-American Mothers' Emotion Socialization Practices Relate Differently to Their Children's Academic and Social-Emotional Competence

    ERIC Educational Resources Information Center

    Nelson, Jackie A.; Leerkes, Esther M.; Perry, Nicole B.; O'Brien, Marion; Calkins, Susan D.; Marcovitch, Stuart

    2013-01-01

    The current study examines whether the relation between mothers' responses to their children's negative emotions and teachers' reports of children's academic performance and social-emotional competence are similar or different for European-American and African-American families. Two hundred mothers (137 European-American, 63…

  8. Lack of Co-occurring Interpersonal Violence Emotionally-Related Difficulties, or Alcohol and Other-Drug Problems among African American Youth with Conduct Disorder.

    ERIC Educational Resources Information Center

    Singleton, Edward G.; Dale, Grady A., Jr.

    Case studies of African American youth with conduct disorder were examined in the context of a descriptive evaluation of co-occurring substance-related problems and mental disorders. The purpose of this study was to extend the findings of the Epidemiologic Catchment Area (ECA) study of the National Institute of Mental Health into the area of…

  9. School Characteristics and Experiences of African American, Hispanic/Latino, and Native American Youth in Rural Communities: Relation to Educational Aspirations

    ERIC Educational Resources Information Center

    Irvin, Matthew J.; Byun, Soo-yong; Meece, Judith L.; Reed, Karla S.; Farmer, Thomas W.

    2016-01-01

    The primary purpose of this study was to examine differences in the school characteristics and experiences of African American, Hispanic/Latino, and Native American youth in rural high schools as well as their relation to educational aspirations. We also investigated the characteristics and experiences of students and their families given that…

  10. Measurement characteristics of activity-related psychosocial measures in 8- to 10-year-old African-American girls in the Girls health Enrichment Multisite Study (GEMS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: This paper presents reliability and validity analyses of physical activity-related psychosocial questionnaires completed by 8- to 10-year-old African-American girls at baseline and follow-up assessments of pilot intervention studies in the Girls health Enrichment Multi-site Study (GEMS)....

  11. A longitudinal examination of the relationship between sexual sensation seeking and STI-related risk factors among African American females.

    PubMed

    Voisin, Dexter R; Tan, Kevin; Diclemente, Ralph J

    2013-04-01

    Sexual sensation seeking has been correlated with STI-related risk factors in numerous cross sectional studies. However, no current studies have examined whether sexual sensation seeking is longitudinally related to a broad spectrum of STI-related factors such as consistent condom use, number of sexual partners, frequency of partner sexual communication, self-efficacy to refuse sex, and fear of condom negotiation. We explored these relationships over a 12-month period among a sample of 715 African American females attending three STI clinics in Georgia that were recruited into a larger randomized clinic intervention study. Utilizing A-CASI technology to assess all self-reported measures and employing general estimation equations while controlling for age, peer norms, school enrollment and employment, major results indicated that higher sexual sensation seeking predicted lower percent of condom use in the last 14 and 60 days, lower consistent condom use and a higher number of lifetime sexual partners. Additionally, higher sexual sensation seeking predicted lower partner sexual communication, diminished self-efficacy to refuse sex, and a higher fear of condom negotiation. Findings suggest that STI/HIV prevention/intervention programs should assess for and target sexual sensation seeking behaviors in such efforts. PMID:23514080

  12. Psychological Misdiagnosis of African Americans.

    ERIC Educational Resources Information Center

    Garretson, Deborah J.

    1993-01-01

    Reviews historical and current problems with making accurate psychological diagnoses of African Americans. Suggests that misdiagnosis is strongly related to pathologization of African-American culture itself. Explores diagnostic process, stereotypes of African-American psychopathology, cultural differences in values and life stressors, and…

  13. Subduction Related Crustal and Mantle Deformations and Their Implications for Plate Dynamics

    NASA Astrophysics Data System (ADS)

    Okeler, Ahmet

    Ocean-continent convergence and subsequent continental collision are responsible for continental growth, mountain building, and severe tectonic events including volcanic eruptions and earthquake activity. They are also key driving forces behind the extensive thermal and compositional heterogeneities at crustal and mantle depths. Active subduction along the Calabrian Arc in southern Italy and the Hellenic Arc are examples of such collisional tectonics. The first part of this thesis examines the subduction related deformations within the crust beneath the southern Apennines. By modeling regional surface wave recordings of the largest temporary deployment in the southern Apennines, a lower-crustal/upper-mantle low-velocity volume extending down to 50 km beneath the mountain chain is identified. The magnitude (˜ 0.4 km/s slower) and anisotropic nature (˜ 10%) of the anomaly suggest the presence of hot and partially molten emplacement that may extend into the upper-crust towards Mt. Vulture, a once active volcano. Since the Apulian basement units are deformed during the compressional and consequent extensional events, our observations favor the "thick-skin" tectonic growth model for the region. In the deeper mantle, active processes are thermodynamically imprinted on the depth and strength of the phase transitions. This thesis examines more than 15000 SS precursors and provides the present-day reflectivity structure and topography associated with these phase transitions. Through case studies I present ample evidence for both slab penetration into the lower mantle (beneath the Hellenic Arc, Kurile Island and South America) and slab stagnation at the bottom of the Mantle Transition Zone (beneath the Tyrrhenian Sea and eastern China). Key findings include (1) thermal anomalies (˜ 200 K) at the base of the MTZ, which represent the deep source for Cenozoic European Rift Zone, Mount Etna and Mount Cameroon volcanism, (2) significant depressions (by 20-40 km) at the bottom

  14. Transportation-related barriers to care among African American women living with HIV/AIDS: “What you getting out of the cab for?”

    PubMed Central

    Evans, Shenell D.; Williams, Bryman E.

    2015-01-01

    Transportation-related problems have been consistently reported as barriers to accessing and remaining in HIV medical care, particularly among African American women living in under-resourced areas. With emphasis on the Southern region of the United States, this commentary presents a brief overview of the HIV/AIDS epidemic among African Americans, barriers to remaining in HIV care, and pilot data from a study conducted among African American women living in Mississippi. A small focus group study was conducted to examine the relative influence of transportation-related barriers on attendance and motivation to attend HIV medical care appointments. Eight African American women (mean age of 43.50, SD = 10.82) who were engaged in medical care participated in one focus group session. Time since diagnosis ranged from 6 to 17 years. Participants reported transportation-related barriers that were generally consistent with previous research, including lack of personal transportation, limited financial resources to pay family and friends for transportation or gasoline, and inconveniences associated with sharing van services with other patients. Participants appeared to have learned how to successfully navigate these barriers in order to remain in care. Interestingly, participants reported significant fear of disclosure related to use of transportation services provided by insurance providers and community organizations. Specifically, many of the women indicated that family, friends, and neighbors questioned them about where they were going and why they used taxis. These types of encounters might influence whether individuals utilize available transportation services. Participants provided several recommendations for improving the transportation system. Additional research is warranted to obtain a more representative sampling of opinions among African American women living in under-resourced areas. PMID:26523160

  15. Characterization of deformation perpendicular to relative plate motion and major faults of the northern San Andreas system using geodetic data

    NASA Astrophysics Data System (ADS)

    Murray, J. R.; Pollitz, F. F.

    2014-12-01

    The northern San Andreas fault system NW of Clear Lake, CA is comprised of the subparallel San Andreas, Maacama, and Bartlett Springs faults. The dominant geodetic signal across the region is right lateral shear strain largely accommodated by infrequent earthquakes on these three faults and creep on the upper 5 km of the latter two. Here we use a newly densified Global Positioning System (GPS) velocity field (Murray et al., 2014) to assess the existence of regional contraction/extension. If present, the degree to which this deformation contributes to oblique slip in future earthquakes or, conversely, is partitioned into off-fault strain has implications for anticipated ground motions and inferred on-fault and off-fault moment deficit rates used in seismic hazard assessment. We inspect the observed horizontal GPS velocity field in a Sierra Nevada-Great Valley (SNGV) fixed frame. To first order the maximum contractile strain rate axis is well-aligned with the maximum compressive stress orientation (Provost and Houston, 2003). Although observed velocities at coastal sites compared to those on the SNGV block show little net strain perpendicular to the direction of Pacific-SNGV relative motion, velocity profiles transecting the three faults show both contraction and extension perpendicular to relative plate motion within the zone between the Great Valley and the coast. To evaluate this signal in the context of fault slip, we consider the residual fault-perpendicular velocity after removing predicted velocities due to the strike-slip component of estimated creep and interseismic locking (Murray et al., 2014). The slip rate model accounts for the fact that the orientations of the three major faults vary along their lengths, the faults are neither uniformly parallel to each other nor to the relative plate motion direction, and strike-slip creep rates vary along strike. In many locations near-fault residual strain rates are small, suggesting geometry and non-uniform creep

  16. Sublatitudinal Isotope Heterogeneity of The Atlantic and Adjacent Continents: A Relation To The Litospheric Plates and Superplums

    NASA Astrophysics Data System (ADS)

    Mironov, Yu. V.; Ryakhovsky, V. M.; Pustovoy, A. A.; Lapidus, I. V.

    Four Sr-Nd-Pb isotope sublatitudinal provinces are chosen in the Atlantic and on ad- jacent continents. They include mid-ocean ridges, oceanic rises and islands, as well as Late Mesozoic - Cenozoic continental rifts and traps. A modified Zindler-Hart "man- tle tetrahedron" (1986) have been used for rock systematics. Its major classification element alongside with known end-members (DM, HIMU, EM1, EM2) is any in- tratetrahedron component F ("focal") (Mironov et al., 2000; Rundquist et al., 2000; Ryakhovsky, 2000). It represents average characteristic of all known intratetrahedron components (FOZO, C, PREMA etc.), updated by methods of multidimensional statis- tics. Northern province includes Mid-Atlantic Ridge from a southern part of Reykjanes ridge up to 24S, numerous islands and rises, located at the same latitudes, Cameroon Line, African and European rifts, Aden and Red sea spreading centres, and also Co- mores in Indian ocean. The main composition dispersion of volcanics from withinplate oceanic and continental structures is determined by mixture of F and HIMU (rarely with admixture EM2). MORB within this area are characterized by stable admixture HIMU. Similar composition have the rocks in Bouvet-Antarctic province, within the limits of which the rises Spiss and Shona, the most southern part of Mid-Atlantic ridge, island Bouvet, an adjacent part of Southwest-Indian Ridge, and also traps and rifts on northern coast of Antarctic Continent are located. The Southern province lies in outlines of known Southern hemisphere DUPAL-anomaly (Hart, 1984). The with- inplate oceanic rocks (Gough, Tristan-da-Kunha, Walvis ridge, Rio Grande Plateau, Discovery) correspond to a mixture F + EM1 (sometimes F + EM1 + EM2) and are similar with traps of Southern America and Africa. Further to east this province is traced on islands and mid-ocean ridges in Indian ocean. MORB of Southern Atlantic and Indian ocean are enriched EM1. The Arctic province includes spreading ridges of

  17. African great apes are naturally infected with polyomaviruses closely related to Merkel cell polyomavirus.

    PubMed

    Leendertz, Fabian H; Scuda, Nelly; Cameron, Kenneth N; Kidega, Tonny; Zuberbühler, Klaus; Leendertz, Siv Aina J; Couacy-Hymann, Emmanuel; Boesch, Christophe; Calvignac, Sébastien; Ehlers, Bernhard

    2011-01-01

    The oncogenic Merkel cell polyomavirus (MCPyV) infects humans worldwide, but little is known about the occurrence of viruses related to MCPyV in the closest phylogenetic relatives of humans, great apes. We analyzed samples from 30 wild chimpanzees and one captive gorilla and identified two new groups of polyomaviruses (PyVs). These new viruses are by far the closest relatives to MCPyV described to date, providing the first evidence of the natural occurrence of PyVs related to MCPyV in wild great apes. Similar to MCPyV, the prevalence of these viruses is relatively high (>30%). This, together with the fact that humans in West and Central Africa frequently hunt and butcher primates, may point toward further MCPyV-like strains spreading to, or already existing in, our species. PMID:21047967

  18. Seismic structure related to the Philippine Sea plate subduction beneath the southwestern Nansei-Shoto (Ryukyu) Trench

    NASA Astrophysics Data System (ADS)

    Nishizawa, A.; Kaneda, K.; Oikawa, M.; Horiuchi, D.; Fujioka, Y.

    2013-12-01

    The northwestern part of the Philippine Sea plate (PSP) is subducting beneath the Nansei-Shoto (Ryukyu) Trench. Earthquakes larger than M8 have not been recorded instrumentally in the southwestern part of the Ryukyu Trench. However, there was a large tsunami killed around 12,000 people in 1771 and the position of the source area has not been established. The direction of the PSP subduction is almost perpendicular to the Ryukyu Trench to the northeast of 126.5 E and changes to oblique to the southwest. Seismicity varies along the trench axis and lower seismicity seems to correspond to the free-air gravity anomaly high region in the forearc at around 126 E. On the other hand, the Okinawa-Luzon fracture zone extending from southwest to northeast on the PSP subducts beneath Ryukyu Trench to the northeast of 126 E and seems to relate to the high gravity anomaly. We carried out seismic experiments to elucidate these inhomogeneous crustal structures along the southwestern part of the trench and provide valuable information on potential source areas for large earthquakes and/or tsunamis. We conducted five seismic lines across southwestern Ryukyu Trench region. Multichannel reflection seismic (MCS) data using 240 ch. and 3000 m long hydrophone streamer were collected for airgun shots at an interval of 50 m. We also deployed ocean bottom seismographs (OBSs) as a receiver at an average interval of 5 km along each line. A tri-gun cluster with a volume of 1,050 (350 * 3) cubic inches (17.2 liters) was used for the reflection surveys and a non-tuned airgun array with a volume of 6,000 (1500 * 4) cubic inches (98 liters) was shot at an interval of 200 m (90 sec) for the wide-angle seismic survey. Depth conversion from the MCS time section was carried out using the refraction results. In this paper, we present the seismic structure related to the PSP subduction in the forearc region of the Nansei-Shoto island arc. The subducting Okinawa-Luzon fracture zone was able to be clearly

  19. Tree Foliar Chemistry in an African Savanna and Its Relation to Life History Strategies and Environmental Filters

    PubMed Central

    Colgan, Matthew S.; Martin, Roberta E.; Baldeck, Claire A.; Asner, Gregory P.

    2015-01-01

    Understanding the relative importance of environment and life history strategies in determining leaf chemical traits remains a key objective of plant ecology. We assessed 20 foliar chemical properties among 12 African savanna woody plant species and their relation to environmental variables (hillslope position, precipitation, geology) and two functional traits (thorn type and seed dispersal mechanism). We found that combinations of six leaf chemical traits (lignin, hemi-cellulose, zinc, boron, magnesium, and manganese) predicted the species with 91% accuracy. Hillslope position, precipitation, and geology accounted for only 12% of the total variance in these six chemical traits. However, thorn type and seed dispersal mechanism accounted for 46% of variance in these chemical traits. The physically defended species had the highest concentrations of hemi-cellulose and boron. Species without physical defense had the highest lignin content if dispersed by vertebrates, but threefold lower lignin content if dispersed by wind. One of the most abundant woody species in southern Africa, Colophospermum mopane, was found to have the highest foliar concentrations of zinc, phosphorus, and δ13C, suggesting that zinc chelation may be used by this species to bind metallic toxins and increase uptake of soil phosphorus. Across all studied species, taxonomy and physical traits accounted for the majority of variability in leaf chemistry. PMID:25993539

  20. Tree foliar chemistry in an African savanna and its relation to life history strategies and environmental filters.

    PubMed

    Colgan, Matthew S; Martin, Roberta E; Baldeck, Claire A; Asner, Gregory P

    2015-01-01

    Understanding the relative importance of environment and life history strategies in determining leaf chemical traits remains a key objective of plant ecology. We assessed 20 foliar chemical properties among 12 African savanna woody plant species and their relation to environmental variables (hillslope position, precipitation, geology) and two functional traits (thorn type and seed dispersal mechanism). We found that combinations of six leaf chemical traits (lignin, hemi-cellulose, zinc, boron, magnesium, and manganese) predicted the species with 91% accuracy. Hillslope position, precipitation, and geology accounted for only 12% of the total variance in these six chemical traits. However, thorn type and seed dispersal mechanism accounted for 46% of variance in these chemical traits. The physically defended species had the highest concentrations of hemi-cellulose and boron. Species without physical defense had the highest lignin content if dispersed by vertebrates, but threefold lower lignin content if dispersed by wind. One of the most abundant woody species in southern Africa, Colophospermum mopane, was found to have the highest foliar concentrations of zinc, phosphorus, and δ(13)C, suggesting that zinc chelation may be used by this species to bind metallic toxins and increase uptake of soil phosphorus. Across all studied species, taxonomy and physical traits accounted for the majority of variability in leaf chemistry. PMID:25993539

  1. Two-stage model of African absolute motion during the last 30 million years

    NASA Astrophysics Data System (ADS)

    Pollitz, Fred F.

    1991-07-01

    The absolute motion of Africa (relative to the hotspots) for the past 30 My is modeled with two Euler vectors, with a change occurring at 6 Ma. Because of the high sensitivity of African absolute motions to errors in the absolute motions of the North America and Pacific plates, both the pre-6 Ma and post-6 Ma African absolute motions are determined simultaneously with North America and Pacific absolute motions for various epochs. Geologic data from the northern Atlantic and hotspot tracks from the African plate are used to augment previous data sets for the North America and Pacific plates. The difference between the pre-6 Ma and post-6 Ma absolute plate motions may be represented as a counterclockwise rotation about a pole at 48 °S, 84 °E, with angular velocity 0.085 °/My. This change is supported by geologic evidence along a large portion of the African plate boundary, including the Red Sea and Gulf of Aden spreading systems, the Alpine deformation zone, and the central and southern mid-Atlantic Ridge. Although the change is modeled as one abrupt transition at 6 Ma, it was most likely a gradual change spanning the period 8-4 Ma. As a likely mechanism for the change, we favor strong asthenospheric return flow from the Afar hotspot towards the southwest; this could produce the uniform southwesterly shift in absolute motion which we have inferred as well as provide a mechanism for the opening of the East African Rift. Comparing the absolute motions of the North America and Pacific plates with earlier estimates, the pole positions are revised by up to 5° and the angular velocities are decreased by 10-20%.

  2. Relative risk of Alzheimer disease and age-at-onset distributions, based on APOE genotypes among elderly African Americans, caucasians, and hispanics in New York City

    SciTech Connect

    Tang, M.X.; Liu, X.H.; Stern, Y.

    1996-03-01

    Apolipoprotein-E {epsilon}4 (APOE-{epsilon}4) has been consistently associated with Alzheimer disease (AD) and may be responsible for an earlier age at onset. We have previously reported a diminished association between APOE-{epsilon}4 and AD in African Americans. Using a new method, which allows inclusion of censored information, we compared relative risks by APOE genotypes in an expanded collection of cases and controls from three ethnic groups in a New York community. The relative risk for AD associated with APOE-{epsilon}4 homozygosity was increased in all ethnic groups (African American relative risk [RR] = 3.0; 95% confidence interval [CI] = 1.5-5.9; Caucasian RR = 7.3, 95% CI = 2.5-21.6; and Hispanic RR = 2.5, 95% CI = 1.1-5.7), compared with those with APOE-{epsilon}3/{epsilon}3 genotypes. The risk was also increased for APOE-{epsilon}4 heterozygous Caucasians (RR = 2.9, 95% CI = 1.7-5.1) and Hispanics (RR = 1.6,95% CI = 1.1-2.3), but not for African Americans (RR = 0.6, 95% CI = 0.4-0.9). The age distribution of the proportion of Caucasians and Hispanics without AD was consistently lower for APOE-{epsilon}4 homozygous and APOE-{epsilon}4 heterozygous individuals than for those with other APOE genotypes. In African Americans this relationship was observed only in APOE-{epsilon}4 homozygotes. These results confirm that APOE genotypes influence the RR of AD in Caucasians and Hispanics. Differences in risk among APOE-{epsilon}4 heterozygote African Americans suggest that other genetic or environmental factors may modify the effect of APOE-{epsilon}4 in some populations. 58 refs., 3 figs., 4 tabs.

  3. Relative risk of Alzheimer disease and age-at-onset distributions, based on APOE genotypes among elderly African Americans, Caucasians, and Hispanics in New York City.

    PubMed Central

    Tang, M. X.; Maestre, G.; Tsai, W. Y.; Liu, X. H.; Feng, L.; Chung, W. Y.; Chun, M.; Schofield, P.; Stern, Y.; Tycko, B.; Mayeux, R.

    1996-01-01

    Apolipoprotein-E epsilon 4 (APOE-epsilon 4) has been consistently associated with Alzheimer disease (AD) and may be responsible for an earlier age at onset. We have previously reported a diminished association between APOE-epsilon 4 and AD in African Americans. Using a new method, which allows inclusion of censored information, we compared relative risks by APOE genotypes in an expanded collection of cases and controls from three ethnic groups in a New York community. The relative risk for AD associated with APOE-epsilon 4 homozygosity was increased in all ethnic groups (African American relative risk [RR]=3.0; 95% confidence interval [CI]=1.5-5.9; Caucasian RR=7.3, 95% CI=2.5-21.6; and Hispanic RR=2.5, 95% CI=1.1-5.7), compared with those with APOE-epsilon 3/epsilon 3 genotypes. The risk was also increased for APOE-epsilon 4 heterozygous Caucasians (RR=2.9, 95% CI=1.7-5.1) and Hispanics (RR=1.6, 95% CI=1.1-2.3), but not for African Americans (RR=0.6, 95% Ci=0.4-0.9). The age distribution of the proportion of Caucasians and Hispanics without AD was consistently lower for APOE-epsilon 4 homozygous and APOE-epsilon 4 heterozygous individuals than for those with other APOE genotypes. In African Americans this relationship was observed only in APOE-epsilon 4 homozygotes. These results confirm that APOE genotypes influence the RR of AD in Caucasians and Hispanics. Differences in risk among APOE-epsilon 4 heterozygote African Americans suggest that other genetic or environmental factors may modify the effect of APOE-epsilon 4 in some populations. PMID:8644717

  4. Paper microzone plates.

    PubMed

    Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

    2009-08-01

    This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader. PMID:19572563

  5. Relations of Transtheoretical Model Stage, Self-Efficacy, and Voluntary Physical Activity in African American Preadolescents

    ERIC Educational Resources Information Center

    Annesi, James J.; Faigenbaum, Avery D.; Westcott, Wayne L.

    2010-01-01

    The transtheoretical model (TTM; Prochaska, DiClemente, & Norcross, 1992) suggests that, at any point, an individual is in one of five stages-of-change related to adopting a behavior. People sequentially advance in stage but may also maintain or even regress, based on personal and environmental factors (Nigg, 2005). A classic study published in…

  6. Knowledge, Beliefs, and Behaviors: Examining Human Papillomavirus-Related Gender Differences among African American College Students

    ERIC Educational Resources Information Center

    Bynum, Shalanda A.; Brandt, Heather M.; Friedman, Daniela B.; Annang, Lucy; Tanner, Andrea

    2011-01-01

    Objective: Given recent approval for administration of a human papillomavirus (HPV) vaccine to men, it is important to assess the HPV-related perspectives of men and women. The purpose of this study was to examine gender differences in HPV knowledge, beliefs, and vaccine acceptance among college students attending 3 historically black…

  7. Assimilation Differences among Africans in America.

    ERIC Educational Resources Information Center

    Dodoo, F. Nii-Amoo

    1997-01-01

    Census data (1990) indicate that male African immigrants earn more than their Caribbean-born counterparts or native-born African Americans, but controlling for relevant earnings-related endowments erases the African advantage and elevates Caribbean earnings above those of the other groups. Also, African (but not Caribbean) university degree…

  8. Clinical depression and HIV risk-related sexual behaviors among African-American adolescent females: unmasking the numbers.

    PubMed

    Brawner, B M; Gomes, M M; Jemmott, L S; Deatrick, J A; Coleman, C L

    2012-01-01

    Clinically depressed and nondepressed African-American adolescent females aged 13-19 years (N=131) were interviewed and surveyed to determine the relationship between depression and HIV risk-related sexual behaviors. Narratives indicate that the psychopathology of depression may create situations where the target population could become exposed to HIV. Specifically, depressed participants described feelings of loneliness, isolation, and wanting somebody to "comfort them" as aspects of depression that affect the decisions they make about sex and relationships. In essence, sex was viewed as a stress reliever, an anti-depressant and a way to increase self-esteem. They shared that even if they did not feel like having sex, they might just "git it over wit" so their partners would stop asking. Some also discussed financial and emotional stability offered by older, more sexually experienced partners. These age-discordant relationships often translated into trusting that their partners knew what was best for their sexual relationships (i.e., having unprotected sex). Sixty-nine percent (n=88) of the sample reported engaging in sexual activity. Given their mean age (16 ± 1.9 years) participants had been sexually active for 2 ± 1.8 years. The adolescents reported an average of 2 ± 1.8 sexual partners within the past three months. Depressed participants reported a higher frequency of having ever had sex (78% vs. 59%, χ(2)=5.236, p=0.022), and had a higher mean number of sexual partners (2 vs. 1, t=-2.023, p= 0.048) and sexual encounters under the influence of drugs and alcohol (8 vs. 2, t=-3.078, p=0.005) in the past three months. The results of this study can guide the modification and/or development of tailored HIV/sexually transmitted infection (STI) prevention programs. The findings provide explicit, psychologically and culturally relevant information regarding the interaction between depression, self-medicating behaviors and risk for HIV/STIs among clinically

  9. Paraffin-related injury in low-income South African communities: knowledge, practice and perceived risk

    PubMed Central

    Swart, Dehran; Hui, Siu-kuen Azor; Simpson, Jennifer; Hobe, Phumla

    2009-01-01

    Abstract Objective To explore what individuals at risk of injury from using paraffin (also known as kerosene) know about paraffin safety, what they do to protect themselves and their families from paraffin-related injury, and how they perceive their risk for such injury. Also, to explore interrelations between these factors and age, sex, education and income. Methods A sample of 238 individuals was randomly recruited from low-income housing districts near Cape Town, South Africa in 2007. Trained research assistants interviewed participants to explore their knowledge about paraffin-related safety and their perceived risk of injury from using paraffin. Researchers inspected participants’ homes to evaluate paraffin safety practices. Descriptive and correlational analyses were conducted. Findings Participants had relatively low levels of knowledge about paraffin-related safety. They had high levels of unsafe practice and their perceived risk of injury was moderate. Knowledge of paraffin safety and safe practices were positively correlated with each other. Greater knowledge showed a negative correlation with the perception of being at risk for injury, but safe practices showed no correlation with perceived risk of injury. Formal education, the number of children in the home and frequency of paraffin use were positively correlated with knowledge but not with safe practices. The only significant correlate to safe practices was greater income, perhaps a reflection of the impact of financial resources on paraffin safety practices. Conclusion To develop successful paraffin safety interventions, it is necessary to understand baseline levels of knowledge, practice and perceived risk of injury among at-risk populations. Our findings could be of value for designing interventions that will increase knowledge, improve safe practices and lead to the accurate perception of the risk of injury from using paraffin. PMID:19784450

  10. AIDS-related knowledge, attitudes and behaviour among South African street youth: reflections on power, sexuality and the autonomous self.

    PubMed

    Swart-Kruger, J; Richter, L M

    1997-09-01

    Street children in South Africa are, in the main, between the ages of 11 and 17 years. Rape, prostitution, sexual bartering and exchange, casual sex and romantic sexual relationships all occur in the experiences of young people who live and work on inner-city streets. In this study, the AIDS-related knowledge, attitudes and behaviour of 141 street youth, living in seven large cities in South Africa, were elicited in focus group discussions. At the time of the study, 79 boys (56%) were living in shelters run by nongovernmental and welfare organisations, while 62 boys (44%) were sleeping "rough". The results, both qualitative and quantitative, indicated that the AIDS knowledge of South African street children was comparable to levels reported for groups of "hard-to-reach" youth in other parts of the world. Fear of HIV infection did not appear in a list of day-to-day priorities constructed by the children, a list dominated by survival concerns with food, money and clothes. However, more than half of the boys conceded that they engaged in sex for money, goods or protection, several boys indicated that they had been raped, and most reported being sexually active with "girlfriends", who themselves frequently engaged in transactional sex. The findings are interpreted in terms of the relationships between power dynamics surrounding race and age, and how they affect self-initiated controls over sexuality and sexual protection. PMID:9255928

  11. Measuring health-related problem solving among African Americans with multiple chronic conditions: application of Rasch analysis.

    PubMed

    Fitzpatrick, Stephanie L; Hill-Briggs, Felicia

    2015-10-01

    Identification of patients with poor chronic disease self-management skills can facilitate treatment planning, determine effectiveness of interventions, and reduce disease complications. This paper describes the use of a Rasch model, the Rating Scale Model, to examine psychometric properties of the 50-item Health Problem-Solving Scale (HPSS) among 320 African American patients with high risk for cardiovascular disease. Items on the positive/effective HPSS subscales targeted patients at low, moderate, and high levels of positive/effective problem solving, whereas items on the negative/ineffective problem solving subscales mostly targeted those at moderate or high levels of ineffective problem solving. Validity was examined by correlating factor scores on the measure with clinical and behavioral measures. Items on the HPSS show promise in the ability to assess health-related problem solving among high risk patients. However, further revisions of the scale are needed to increase its usability and validity with large, diverse patient populations in the future. PMID:25319236

  12. Parent & Family Influences on Adopting Healthy Weight-Related Behaviors: Views and Perceptions of Obese African-American Female Adolescents.

    PubMed

    Pratt, Keeley J; McRitchie, Susan; Collier, David N; Lutes, Lesley D; Sumner, Susan

    2015-06-01

    RTI International is acknowledged for supporting the time of Susan McRitchie, Keeley Pratt and Susan Sumner to participate in the design, execution, or analysis of this study. East Carolina University would like to acknowledge Brittney France for being a triangulated investigator for the qualitative analysis and to the Pitt Memorial Hospital Foundation for financial support of the healthy lifestyles camp. Our purpose was to evaluate the views of obese African-American (AA) female adolescents concerning parent and family factors relating to obesity and a healthy lifestyle. Obese AA female adolescents enrolled in a residential healthy lifestyle program completed inventories measuring family functioning and perceptions of parenting styles, and participated in focus groups to identify themes regarding parent and family involvement in healthy lifestyle change. The majority of participants' mothers were scored as "inductive/authoritative" and fathers were "indulgent". Mothers reportedly were seen as more likely to encourage dieting to control weight than fathers. Common themes of the focus groups included a desire for family involvement, identification of family behaviors that were supportive as well as those which were perceived as unhelpful. Though generalizability of these results is limited by a homogenous small sample size, our results suggest that obese adolescents seeking weight loss treatment desire significant family involvement in their efforts. PMID:27269493

  13. A Re-Examination of Cultural Factors that Mitigate Risk and Promote Resilience in Relation to African American Suicide: A Review of the Literature and Recommendations for Future Research

    ERIC Educational Resources Information Center

    Utsey, Shawn O.; Hook, Joshua N.; Stanard, Pia

    2007-01-01

    Suicide among African Americans has been acknowledged by the U.S. Surgeon General as a growing crisis. However, suicide remains understudied in this population. In this article, the authors examine the literature related to cultural protective factors that buffer African Americans from suicide risk. They present an overview of suicide among…

  14. Comparing HIV-related symbolic stigma in six African countries: social representations in young people’s narratives

    PubMed Central

    Winskell, Kate; Hill, Elizabeth; Obyerodhyambo, Oby

    2011-01-01

    HIV-related symbolic stigma arises from moralistic value judgements attached to people living with HIV and has negative consequences from both public health and human rights perspectives. Relatively little is known about cross-national variation in symbolic stigma. With the purpose of informing stigma reduction efforts within and across settings, we compared social representations of HIV in six African countries with estimated adult HIV prevalence rates ranging from 1 to 33%. Our study used a unique data source, namely a stratified random sample (n=586, ~5%) from 11,354 creative ideas contributed from six countries to a continent-wide HIV-related scriptwriting contest held between February and April2005. The narratives were written by equal numbers of males and females aged 10–24 in urban and rural areas of Swaziland, Namibia, Kenya, South-East Nigeria, Burkina Faso and Senegal. We combined three analytical approaches: descriptive statistics on certain quantifiable characteristics of the narratives, thematic data analysis, and a narrative-based approach. The association of HIV with outsiders (“othering”)and preoccupation with the circumstances of infection are more common in lower prevalence countries but vary substantially in tone depending on the sociocultural context. The highest proportion both of moralising narratives and of narratives with pessimistic outcomes come from South-East Nigeria and, to a lesser extent, from Kenya, countries with prevalence levels of 3.9 and 6.1% respectively, in which evangelical Christian movements, including Pentecostalism, have sizeable followings. The data provide a rare cross-cultural overview of symbolic stigma, identify country-specific needs, and point to strategies for future programming. Social representations from the highest prevalence countries, Swaziland and Namibia, and from lower prevalence Burkina Faso offer potential models for the framing of HIV in ways that serve to increase social proximity and counteract

  15. Multiple mantle upwellings in the transition zone beneath the northern East-African Rift system from relative P-wave travel-time tomography

    NASA Astrophysics Data System (ADS)

    Civiero, Chiara; Hammond, James O. S.; Goes, Saskia; Fishwick, Stewart; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, J.-Michael; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rümpker, Georg; Stuart, Graham W.

    2015-09-01

    Mantle plumes and consequent plate extension have been invoked as the likely cause of East African Rift volcanism. However, the nature of mantle upwelling is debated, with proposed configurations ranging from a single broad plume connected to the large low-shear-velocity province beneath Southern Africa, the so-called African Superplume, to multiple lower-mantle sources along the rift. We present a new P-wave travel-time tomography model below the northern East-African, Red Sea, and Gulf of Aden rifts and surrounding areas. Data are from stations that span an area from Madagascar to Saudi Arabia. The aperture of the integrated data set allows us to image structures of ˜100 km length-scale down to depths of 700-800 km beneath the study region. Our images provide evidence of two clusters of low-velocity structures consisting of features with diameter of 100-200 km that extend through the transition zone, the first beneath Afar and a second just west of the Main Ethiopian Rift, a region with off-rift volcanism. Considering seismic sensitivity to temperature, we interpret these features as upwellings with excess temperatures of 100 ± 50 K. The scale of the upwellings is smaller than expected for lower mantle plume sources. This, together with the change in pattern of the low-velocity anomalies across the base of the transition zone, suggests that ponding or flow of deep-plume material below the transition zone may be spawning these upper mantle upwellings. This article was corrected on 28 SEP 2015. See the end of the full text for details.

  16. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores

    PubMed Central

    Dalerum, Fredrik; Miranda, Maria

    2016-01-01

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated. PMID:26911226

  17. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores.

    PubMed

    Dalerum, Fredrik; Miranda, Maria

    2016-01-01

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated. PMID:26911226

  18. Relations between albedos and emissivities from MODIS and ASTER data over North African Desert

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Dickinson, R. E.; Ogawa, K.; Tian, Y.; Jin, M.; Schmugge, T.; Tsvetsinskaya, E.

    2003-10-01

    This paper analyzes relations among MODIS surface albedos, ASTER broadband (3-14 μm) emissivities, and a soil taxonomy map over the arid areas of Algeria, Libya, and Tunisia in North Africa at 30 second (about 1 km) and 2 minute (about 4 km) spatial resolutions. The MODIS albedo data are from 7 spectral bands and 3 broadbands during dust-free seasons and the emissivity data are derived from a linear combination of the waveband emissivities of the ASTER five thermal infrared channels. Both albedo and emissivity data in the study region show similar considerable spatial variability, larger than assumed by most climate models, and such variability is related to the surface types (sands, rock, and soil orders). Emissivity over bare soils exhibits statistically significant correlations with albedos at both broadbands and most of spectral bands and decreases linearly with albedos. Albedo and emissivity are more strongly correlated with each other than either is to the surface types, apparently because of their higher resolution either spatially or in surface mineralogy. This paper provides guidance for the possible inclusion of such correlation to specify albedo and emissivity in climate models.

  19. Distribution and migration of aftershocks of the 2010 Mw 7.4 Ogasawara Islands intraplate normal-faulting earthquake related to a fracture zone in the Pacific plate

    NASA Astrophysics Data System (ADS)

    Obana, Koichiro; Takahashi, Tsutomu; No, Tetsuo; Kaiho, Yuka; Kodaira, Shuichi; Yamashita, Mikiya; Sato, Takeshi; Nakamura, Takeshi

    2014-04-01

    describe the aftershocks of a Mw 7.4 intraplate normal-faulting earthquake that occurred 150 km east Ogasawara (Bonin) Islands, Japan, on 21 December 2010. It occurred beneath the outer trench slope of the Izu-Ogasawara trench, where the Pacific plate subducts beneath the Philippine Sea plate. Aftershock observations using ocean bottom seismographs (OBSs) began soon after the earthquake and multichannel seismic reflection surveys were conducted across the aftershock area. Aftershocks were distributed in a NW-SE belt 140 km long, oblique to the N-S trench axis. They formed three subparallel lineations along a fracture zone in the Pacific plate. The OBS observations combined with data from stations on Chichi-jima and Haha-jima Islands revealed a migration of the aftershock activity. The first hour, which likely outlines the main shock rupture, was limited to an 80 km long area in the central part of the subsequent aftershock area. The first hour activity occurred mainly around, and appears to have been influenced by, nearby large seamounts and oceanic plateau, such as the Ogasawara Plateau and the Uyeda Ridge. Over the following days, the aftershocks expanded beyond or into these seamounts and plateau. The aftershock distribution and migration suggest that crustal heterogeneities related to a fracture zone and large seamounts and oceanic plateau in the incoming Pacific plate affected the rupture of the main shock. Such preexisting structures may influence intraplate normal-faulting earthquakes in other regions of plate flexure prior to subduction.

  20. Energy, protein, and zinc nutriture of rural African children in relation to some anthropometric indices

    SciTech Connect

    Ferguson, E.L.; Gibson, R.S.; Osei-Opare, F.; Opare-Obisaw, C.; Thompson, L.U. Univ. of Ghana, Legon Univ. of Toronto, Ontario )

    1991-03-11

    Heights, weights, arm circumferences, and triceps skinfold thicknesses of 66 Malawian and 148 Ghanaian preschool children were measured during 3 seasons. Their seasonal energy, protein, Ca, Zn, dietary fiber and phytate intakes were estimated from 3-day weighed records, using analyzed and literature food composition values. Seasonal hair Zn concentrations were analyzed by instrumental neutron activation analyses, The mean annual intakes for Malawian compared to Ghanaian children were higher for energy protein, and Zn. Cereals contributed a higher proportion of the total energy intake in the Malawian compared to the Ghanaian diets. A higher percentage of the Malawian children had height-for-age Z-scores below {minus}2SD, but a lower percentage had weight-for-height Z-scores below {minus}1SD compared to their Ghanaian counterparts. These differences may, in part be related to the high cereal intakes of the Malawian children.

  1. Associations between Common Variants in Iron-Related Genes with Haematological Traits in Populations of African Ancestry

    PubMed Central

    Tanaka, Toshiko; Towers, G. Wayne; Verhoef, Hans; Veenemans, Jacobien; Talsma, Elise F.; Harryvan, Jan; Boekschoten, Mark V.; Feskens, Edith J.; Melse-Boonstra, Alida

    2016-01-01

    Background Large genome-wide association (GWA) studies of European ancestry individuals have identified multiple genetic variants influencing iron status. Studies on the generalizability of these associations to African ancestry populations have been limited. These studies are important given interethnic differences in iron status and the disproportionate burden of iron deficiency among African ancestry populations. Methods We tested the associations of 20 previously identified iron status-associated single nucleotide polymorphisms (SNPs) in 628 Kenyans, 609 Tanzanians, 608 South Africans and 228 African Americans. In each study, we examined the associations present between 20 SNPs with ferritin and haemoglobin, adjusting for age, sex and CRP levels. Results In the meta analysis including all 4 African ancestry cohorts, we replicated previously reported associations with lowered haemoglobin concentrations for rs2413450 (β = -0.19, P = 0.02) and rs4820268 (β = -0.16, P = 0.04) in TMPRSS6. An association with increased ferritin concentrations was also confirmed for rs1867504 in TF (β = 1.04, P = <0.0001) in the meta analysis including the African cohorts only. Conclusions In all meta analyses, we only replicated 4 of the 20 single nucleotide polymorphisms reported to be associated with iron status in large GWA studies of European ancestry individuals. While there is now evidence for the associations of a number of genetic variants with iron status in both European and African ancestry populations, the considerable lack of concordance highlights the importance of continued ancestry-specific studies to elucidate the genetic underpinnings of iron status in ethnically diverse populations. PMID:27332551

  2. East African Rift

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Places where the earth's crust has formed deep fissures and the plates have begun to move apart develop rift structures in which elongate blocks have subsided relative to the blocks on either side. The East African Rift is a world-famous example of such rifting. It is characterized by 1) topographic deep valleys in the rift zone, 2) sheer escarpments along the faulted walls of the rift zone, 3) a chain of lakes within the rift, most of the lakes highly saline due to evaporation in the hot temperatures characteristic of climates near the equator, 4) voluminous amounts of volcanic rocks that have flowed from faults along the sides of the rift, and 5) volcanic cones where magma flow was most intense. This example in Kenya displays most of these features near Lake Begoria.

    The image was acquired December 18, 2002, covers an area of 40.5 x 32 km, and is located at 0.1 degrees north latitude, 36.1 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  3. Two jacalin-related lectins from seeds of the African breadfruit (Treculia africana L.).

    PubMed

    Shimokawa, Michiko; Nsimba-Lubaki, Shadrack Makuta; Hayashi, Namiko; Minami, Yuji; Yagi, Fumio; Hiemori, Keiko; Tateno, Hiroaki; Hirabayashi, Jun

    2014-01-01

    Two jacalin-related lectins (JRLs) were purified by mannose-agarose and melibiose-agarose from seeds of Treculia africana. One is galactose-recognizing JRL (gJRL), named T. africana agglutinin-G (TAA-G), and another one is mannose-recognizing JRL (mJRL), TAA-M. The yields of the two lectins from the seed flour were approximately 7.0 mg/g for gJRL and 7.2 mg/g for mJRL. The primary structure of TAA-G was determined by protein sequencing of lysyl endopeptic peptides and chymotryptic peptides. The sequence identity of TAA-G to other gJRLs was around 70%. Two-residue insertion was found around the sugar-binding sites, compared with the sequences of other gJRLs. Crystallographic studies on other gJRLs have shown that the primary sugar-binding site of gJRLs can accommodate Gal, GalNAc, and GalNAc residue of T-antigen (Galβ1-3GalNAcα-). However, hemagglutination inhibition and glycan array showed that TAA-G did not recognize GalNAc itself and T-antigen. TAA-G preferred melibiose and core 3 O-glycan. PMID:25155899

  4. African hot spot volcanism: small-scale convection in the upper mantle beneath cratons.

    PubMed

    King, S D; Ritsema, J

    2000-11-10

    Numerical models demonstrate that small-scale convection develops in the upper mantle beneath the transition of thick cratonic lithosphere and thin oceanic lithosphere. These models explain the location and geochemical characteristics of intraplate volcanos on the African and South American plates. They also explain the presence of relatively high seismic shear wave velocities (cold downwellings) in the mantle transition zone beneath the western margin of African cratons and the eastern margin of South American cratons. Small-scale, edge-driven convection is an alternative to plumes for explaining intraplate African and South American hot spot volcanism, and small-scale convection is consistent with mantle downwellings beneath the African and South American lithosphere. PMID:11073447

  5. Pregnancy related breast diseases in a developing African country: Initial Sonographic Evaluation

    PubMed Central

    Adeniji-Sofoluwe, Adenike Temitayo; Obajimi, Gbolahan Oladele; Obajimi, Millicent Olubunmi

    2015-01-01

    Benign diseases are more common than malignant diseases in pregnant and lactating women. Fibroadenomas are the most commonly identified benign breast tumour in pregnant and lactating women. Pregnancy related breast cancer is defined as breast cancer that occurs during pregnancy or within 1 year of delivery. Its incidence is estimated at 1 in 3000 to 1 in 10 000 pregnancies. Several reproductive factors like age at menarche, age at menopause, age at full-term pregnancy, parity, age at any birth and spacing of pregnancies, breast feeding, characteristics of the menstrual cycle, infertility, spontaneous and induced abortions, characteristics of the menstrual cycle and infertility are some of the factors that have been incriminated as risk factors for breast cancer. We sought to describe the predominant breast pattern, sonographic array of pregnancy related breast diseases in women referred to the breast imaging unit in the department of Radiology at the University College Hospital, Ibadan south west Nigeria. Socio-demographic characteristics in these women were also evaluated. Archived images were reviewed and documented and data was analysed with SPSS version 17 and presented with descriptives. In this descriptive study, we retrospectively retrieved the sonomammographic records of 21 women (pregnant or lactating) referred to and imaged in the department of radiology, University college hospital Ibadan, between 2006 and 2013. Diagnostic breast sonograms performed by MO and ATS; Consultant radiologists with 7-10 years’ experience utilized a 7-10 MHz transducer of the General electric GE Logiq P5 machine for the scans. Twenty-one women with ages between 22-42 years (Mean 31.4 ±5.4 SD) pregnant or lactating were referred to the radiology department for sonomammographic evaluation. Majority of the women were in the 3rd decade. Referral was mainly (11) by family Physicians from the general outpatient clinic, 5 were self-referred, 2 from radiotherapy department, 2 from

  6. Incidence and Determinants of Nevirapine and Efavirenz-Related Skin Rashes in West Africans: Nevirapine's Epitaph?

    PubMed Central

    Sarfo, Fred Stephen; Sarfo, Maame Anima; Norman, Betty; Phillips, Richard; Chadwick, David

    2014-01-01

    Non-nucleoside reverse transcriptase inhibitor (NNRTI) associated rash is common and frequently leads to discontinuation of NNRTIs. This study assessed the risk of developing rashes and discontinuing NNRTIs and associated factors in a large clinic in central Ghana. In this retrospective cohort study, clinical data were obtained in patients starting efavirenz or nevirapine between 2004–2010. Factors associated with rashes were explored using a multivariate Cox proportional hazards regression model. Of 3,999 patients who started NNRTI-based ART, 281 (7.0%) experienced at least one episode of NNRTI-related rash with an incidence of 2.63 events/100 person-years, occurring in 10.2% and 5.6% of patients taking nevirapine and efavirenz respectively. Most rashes (94%) were grade 1 or 2 and were reported a median of 2 months following initiation of ART. In multivariate analysis developing a rash was associated with nevirapine use (aHR 1.67, 95% CI 1.28–2.10), female gender (aHR of 1.39, 95% CI 1.01–1.92) and lower baseline CD4 counts (aHR 0.88, 95% CI 0.82–0.95 per 50 cells/mm3 increment). Patients with nevirapine-associated rash were 11 times more likely to discontinue treatment as patients with efavirenz-associated rash. In contrast to findings in other studies, NNRTI-associated rashes in Ghanaians appear more common in patients with lower baseline CD4 counts. Given the increased frequency of rashes with nevirapine and subsequent discontinuations in many patients, along with other treatment-limiting toxicities, this provides further impetus for the replacement of nevirapine by efavirenz as the first-line NNRTI treatment of choice in Africa. PMID:24728406

  7. Incidence and determinants of nevirapine and efavirenz-related skin rashes in West Africans: nevirapine's epitaph?

    PubMed

    Sarfo, Fred Stephen; Sarfo, Maame Anima; Norman, Betty; Phillips, Richard; Chadwick, David

    2014-01-01

    Non-nucleoside reverse transcriptase inhibitor (NNRTI) associated rash is common and frequently leads to discontinuation of NNRTIs. This study assessed the risk of developing rashes and discontinuing NNRTIs and associated factors in a large clinic in central Ghana. In this retrospective cohort study, clinical data were obtained in patients starting efavirenz or nevirapine between 2004-2010. Factors associated with rashes were explored using a multivariate Cox proportional hazards regression model. Of 3,999 patients who started NNRTI-based ART, 281 (7.0%) experienced at least one episode of NNRTI-related rash with an incidence of 2.63 events/100 person-years, occurring in 10.2% and 5.6% of patients taking nevirapine and efavirenz respectively. Most rashes (94%) were grade 1 or 2 and were reported a median of 2 months following initiation of ART. In multivariate analysis developing a rash was associated with nevirapine use (aHR 1.67, 95% CI 1.28-2.10), female gender (aHR of 1.39, 95% CI 1.01-1.92) and lower baseline CD4 counts (aHR 0.88, 95% CI 0.82-0.95 per 50 cells/mm³ increment). Patients with nevirapine-associated rash were 11 times more likely to discontinue treatment as patients with efavirenz-associated rash. In contrast to findings in other studies, NNRTI-associated rashes in Ghanaians appear more common in patients with lower baseline CD4 counts. Given the increased frequency of rashes with nevirapine and subsequent discontinuations in many patients, along with other treatment-limiting toxicities, this provides further impetus for the replacement of nevirapine by efavirenz as the first-line NNRTI treatment of choice in Africa. PMID:24728406

  8. HIV-Related Discrimination among Grade Six Students in Nine Southern African Countries

    PubMed Central

    Maughan-Brown, Brendan; Spaull, Nicholas

    2014-01-01

    Background HIV-related stigmatisation and discrimination by young children towards their peers have important consequences at the individual level and for our response to the epidemic, yet research on this area is limited. Methods We used nationally representative data to examine discrimination of HIV-positive children by grade six students (n = 39,664) across nine countries in Southern Africa: Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia and Zimbabwe. Descriptive statistics are used to compare discrimination by country, gender, geographic location and socioeconomic status. Multivariate logistic regression is employed to assess potential determinants of discrimination. Results The levels and determinants of discrimination varied significantly between the nine countries. While one in ten students in Botswana, Malawi, South Africa and Swaziland would “avoid or shun” an HIV positive friend, the proportions in Lesotho, Mozambique, Zambia and Zimbabwe were twice as high (approximately 20%). A large proportion of students believed that HIV positive children should not be allowed to continue to attend school, particularly in Zambia (33%), Lesotho (37%) and Zimbabwe (42%). The corresponding figures for Malawi and Swaziland were significantly lower at 13% and 12% respectively. Small differences were found by gender. Children from rural areas and poorer schools were much more likely to discriminate than those from urban areas and wealthier schools. Importantly, we identified factors consistently associated with discrimination across the region: students with greater exposure to HIV information, better general HIV knowledge and fewer misconceptions about transmission of HIV via casual contact were less likely to report discrimination. Conclusions Our study points toward the need for early interventions (grade six or before) to reduce stigma and discrimination among children, especially in schools situated in rural areas and poorer

  9. Work related musculoskeletal disorders and ergonomic stressors in the South African workforce.

    PubMed Central

    Schierhout, G H; Meyers, J E; Bridger, R S

    1995-01-01

    OBJECTIVES--The main objective of this study was to investigate exposure-response relations between adverse musculoskeletal outcomes and ergonomic exposure variables. METHODS--A cross sectional analytical study was conducted in 11 factories from seven sectors of manufacturing industry in South Africa. Exposure to workplace ergonomic stressors was assessed in factory floor jobs (n = 46) with a simple low technology observational model. Repetition, force, static posture, dynamic movement, and other job exposures were measured. Data of adverse musculoskeletal outcome and data on potential confounders and effect modifiers were obtained from subjects (n = 401) randomly sampled from each job category with a questionnaire given by interviewers. RESULTS--High prevalences of regional musculoskeletal pain were found with substantial variability between industries. Sex was the only individual risk factor (after adjustment for potential confounders and effect modifiers) that was significantly associated with regional pain. Ergonomic exposures in the workplace were significantly associated with musculoskeletal pain of the neck and shoulders odds ratio (OR) 5.38 (95% confidence interval (95% CI) 1.16 to 25.0) for repetition, and OR 3.91 (95% CI 1.11 to 13.7) for seated compared with standing work; pain of the wrists and hands OR 10.2 (95% CI 1.39 to 75.6) for high summed score of dynamic postures of the wrist). CONCLUSIONS--This study indicates good predictive ability to reduce ergonomic stress with the exposure model, simple surveillance methods, and educational programmes in the workplace. Further study on sampling strategies and refinement of dimensions of ergonomic stressors are needed. PMID:7697140

  10. Basement control in the development of the early cretaceous West and Central African rift system

    NASA Astrophysics Data System (ADS)

    Maurin, Jean-Christophe; Guiraud, René

    1993-12-01

    The structural framework of the Precambrian basement of the West and Central African Rift System (WCARS) is described in order to examine the role of ancient structures in the development of this Early Cretaceous rift system. Basement structures are represented in the region by large Pan-African mobile belts (built at ca. 600 Ma) surrounding the > 2 Ga West African, Congo and Sao Francisco cratons. Except for the small Gao trough (eastern Mali) located near the contact nappe of the Pan-African Iforas suture zone along the edge of the West African craton, the entire WCARS is located within the internal domains of the Pan-African mobile belts. Within these domains, two main structural features occur as the main basement control of the WCARS: (1) an extensive network of near vertical shear zones which trend north-south through the Congo, Brazil, Nigeria, Niger and Algeria, and roughly east-west through northeastern Brazil and Central Africa. The shear zones correspond to intra-continental strike-slip faults which accompanied the oblique collision between the West African, Congo, and Sao Francisco cratons during the Late Proterozoic; (2) a steep metamorphic NW-SE-trending belt which corresponds to a pre-Pan-African (ca. 730 Ma) ophiolitic suture zone along the eastern edge of the Trans-Saharian mobile belt. The post-Pan-African magmatic and tectonic evolution of the basement is also described in order to examine the state of the lithosphere prior to the break-up which occurred in the earliest Cretaceous. After the Pan-African thermo-tectonic event, the basement of the WCARS experienced a long period of intra-plate magmatic activity. This widespread magmatism in part relates to the activity of intra-plate hotspots which have controlled relative uplift, subsidence and occasionally block faulting. During the Paleozoic and the early Mesozoic, this tectonic activity was restricted to west of the Hoggar, west of Aïr and northern Cameroon. During the Late Jurassic

  11. Social and Linguistic Input in Low-Income African American Mother-Child Dyads from 1 Month through 2 Years: Relations to Vocabulary Development

    ERIC Educational Resources Information Center

    Shimpi, Priya M.; Fedewa, Alicia; Hans, Sydney

    2012-01-01

    The relation of social and linguistic input measures to early vocabulary development was examined in 30 low-income African American mother-infant pairs. Observations were conducted when the child was 0 years, 1 month (0;1), 0;4, 0;8, 1;0, 1;6, and 2;0. Maternal input was coded for word types and tokens, contingent responsiveness, and…

  12. Relation of plasma calcium to total protein and albumin in African grey (Psittacus erithacus) and Amazon (Amazona spp.) parrots.

    PubMed

    Lumeij, J T

    1990-10-01

    A significant correlation was found between total calcium and albumin concentration in the plasma of 70 African grey parrots (r=0.37; P<0.05). A correlation formula for plasma calcium concentration in the African grey parrot was derived on the basis of the concentration of albumin: Adjusted Ca (mmol/1) = Ca (mmol/1) - 0.015 Albumin (g/1) + 0.4. About 14% of the variability in calcium was attributable to the change in the concentration of plasma albumin concentration (R2=0.137). The correlation between calcium and total protein in African greys and between calcium and albumin and calcium and total protein in Amazons was not significant. PMID:18679980

  13. Magmatic and related mineral deposits of the Pan-African Saldania belt in the Western Cape Province, South Africa

    NASA Astrophysics Data System (ADS)

    Rozendaal, A.; Scheepers, R.

    1995-07-01

    Mineral deposits and prospects of the Pan-African Saldania orogenic belt in the Western Cape Province, South Africa, are reviewed. The polyphase, deformed, low-grade metamorphosed, volcano-sedimentary Malmesbury Group constitutes a complex, poorly understood supracrustal sequence that has been loosely subdivided into the Tygerberg, Swartland and Boland tectono-stratigraphic terranes on the basis of NW-trending fault zones. Syn- and post-tectonic granitoids of the Cape Granite Suite selectively intruded these terranes. Early S-types preferred the Tygerberg terrane, whereas the later I-types dominate the remaining areas. Anorogenic A-type granites, however, occur in all three terranes. Despite the absence of operating base or precious metal mines in the area, this study has established at least four metal associations directly or indirectly related to the intrusions: i) Cassiterite-wolframite (±Au, Cu, Mo, Zn, As, Fe-sulphides) in quartz and quartz/aplite veins hosted by tour-malinized and locally greissenized S-type granite. Similar exo-granitic veins occur in proximal metamorphites; ii) Juxtaposed, disseminated, stockwork breccia and vein style CuMoFe(Au)-sulphide mineralization hosted by mafic- to intermediate-intrusions of high-K calc-alkaline, I-type affinity; iii) CuMoAu-sulphides hosted by hydraulic breccia pipes, stocks and veins occurring in anorogenic A-type alkali feldspar granites and amphibole quartz syenites; iv) Scheelite with minor CuMoAu-sulphides associated with endo- and exo-skams spatially related to I-type monzogranite, granite and alkali feldspar granite. The first three associations occur along the Yzerfontein-Helderberg-zone, a 180 km lineament in the Tygerberg terrane, exploited by syn-, late- and post-tectonic intrusions and their related mineralization. The fourth association is typical of the Boland terrane. The spatial and temporal relationships among the various metal associations are interpreted as the result of

  14. Reduced reproductive function in wild baboons (Papio hamadryas anubis) related to natural consumption of the African black plum (Vitex doniana).

    PubMed

    Higham, James P; Ross, Caroline; Warren, Ymke; Heistermann, Michael; MacLarnon, Ann M

    2007-09-01

    Several authors have suggested that the consumption of plant compounds may have direct effects on wild primate reproductive biology, but no studies have presented physiological evidence of such effects. Here, for two troops of olive baboons (Papio hamadryas anubis) at Gashaka-Gumti National Park, Nigeria, we show major seasonal increases in levels of fecal progesterone metabolites in females, and provide evidence that this is linked to the consumption of natural plant compounds. Increases in fecal progestogen excretion occurred seasonally in all females, in all reproductive states, including lactation. Detailed feeding data on the study animals showed that only one food species is consumed by both troops at the time of observed progestogen peaks, and at no other times of the year: the African black plum, Vitex doniana. Laboratory tests demonstrated the presence of high concentrations of progestogen-like compounds in V. doniana. Together with published findings linking the consumption of a related Vitex species (Vitex agnus castus) to increased progestogen levels in humans, our data suggest that natural consumption of V. doniana was a likely cause of the observed increases in progestogens. Levels of progestogen excretion in the study baboons during periods of V. doniana consumption are higher than those found during pregnancy, and prevent the expression of the sexual swelling, which is associated with ovulatory activity. As consortship and copulatory activity in baboons occur almost exclusively in the presence of a sexual swelling, V. doniana appears to act on cycling females as both a physiological contraceptive (simulating pregnancy in a similar way to some forms of the human contraceptive pill) and a social contraceptive (preventing sexual swelling, thus reducing association and copulation with males). The negative effects of V. doniana on reproduction may be counter-balanced by the wide-range of medicinal properties attributed to plants in this genus. This is

  15. Maternal anthropometry and infant feeding practices in Israel in relation to growth in infancy: the North African Infant Feeding Study.

    PubMed

    Fawzi, W W; Forman, M R; Levy, A; Graubard, B I; Naggan, L; Berendes, H W

    1997-06-01

    Relations between maternal anthropometric status during pregnancy and infant feeding practices and growth from birth through the first 6 mo of life were examined in a cohort of 351 Israeli mother-infant pairs of North African descent. Maternal weight, height, and triceps skinfold thicknesses were determined at 6 and 9 mo of pregnancy, while infants' weights and lengths were measured at birth and at 1, 2, 3, and 6 mo of age with concurrent collection of age-specific maternal-reported infant feeding data. On the basis of multiple-linear-regression analysis that adjusted for potential covariates, mean maternal weight at the first prenatal visit and at 6 and 9 mo of pregnancy were positively associated with birth length (P for trend in all cases < 0.0001) and with linear growth between birth and 1, 3, and 6 mo of age. Maternal skinfold thickness at 9 mo of pregnancy and maternal height were also significantly associated with birth length. Moreover, maternal height, weight, and skinfold thickness at 6 and 9 mo of pregnancy were positively associated with mean birth weight. After adjustment for morbidity in the past month and other covariates, infants breast-fed exclusively had greater attained weight and weight gain in the first 3 mo compared with infants who were bottle-fed exclusively, breast-fed and bottle-fed, or solid-fed exclusively. These findings underscore the need for programs that improve the nutritional status of women before, during, and after pregnancy, and encourage exclusive breast-feeding of infants for at least the first 3 mo of life. PMID:9174468

  16. Negro, Black, Black African, African Caribbean, African American or what? Labelling African origin populations in the health arena in the 21st century.

    PubMed

    Agyemang, Charles; Bhopal, Raj; Bruijnzeels, Marc

    2005-12-01

    Broad terms such as Black, African, or Black African are entrenched in scientific writings although there is considerable diversity within African descent populations and such terms may be both offensive and inaccurate. This paper outlines the heterogeneity within African populations, and discusses the strengths and limitations of the term Black and related labels from epidemiological and public health perspectives in Europe and the USA. This paper calls for debate on appropriate terminologies for African descent populations and concludes with the proposals that (1) describing the population under consideration is of paramount importance (2) the word African origin or simply African is an appropriate and necessary prefix for an ethnic label, for example, African Caribbean or African Kenyan or African Surinamese (3) documents should define the ethnic labels (4) the label Black should be phased out except when used in political contexts. PMID:16286485

  17. Trajectories of Intrusive Parenting During Infancy and Toddlerhood as Predictors of Rural, Low-Income African American Boys’ School-Related Outcomes

    PubMed Central

    Clincy, Amanda R.; Mills-Koonce, W. Roger

    2015-01-01

    Stability and change in maternal intrusiveness during early childhood is rarely explored, particularly within African American families. The current study examined the prediction of maternal intrusiveness during the first 3 years of life among mothers of rural, low-income African American boys and its relation to school-related outcomes. Observations of mothers (N=230) interacting with children at 6, 24, and 36 months were coded and analyzed. Predictors of the trajectories and child outcomes were assessed using questionnaires and various tasks. On average, mothers of African American boys increased in intrusiveness across the first 3 years of life. Cumulative sociodemographic risk was associated with initial levels of intrusiveness, and child fearfulness and maternal negative regard predicted increases in intrusiveness overtime. After controlling for sociodemographic risk, child temperament, and parental negativity, increases in intrusiveness over the first 3 years of life were associated with lower levels of expressive communication, inhibitory control, and intellectual functioning but not with attention focusing. Comprehensive parenting intervention efforts aimed toward improving children’s outcomes must take into consideration the broader socioeconomic and affective context in which parenting behaviors occur, as well as stability and change in parenting over time. PMID:23889012

  18. The Relations of Stressful Events and Nonacademic Future Expectations in African American Adolescents: Gender Differences in Parental Monitoring

    ERIC Educational Resources Information Center

    Cunningham, Michael; Mars, Dustin E.; Burns, Lateela J.

    2012-01-01

    Urban African American high school students (N = 206) completed a study to examine gender differences in parental monitoring and the effect on the relationship between exposure to stressful life events and nonacademic future expectations. Participant's ages range from 13 to 18 (M = 15.78, SD = 1.19). Participants reported high exposure to…

  19. Maternal Control and Sensitivity, Child Gender, and Maternal Education in Relation to Children's Behavioral Outcomes in African American Families

    ERIC Educational Resources Information Center

    Tamis-LeMonda, Catherine S.; Briggs, Rahil D.; McClowry, Sandra G.; Snow, David L.

    2009-01-01

    This study examined relationships between mother-child interactions and children's behaviors in 119 urban African American mothers and their 6-7 year old children. Interactions during a cooking task and a follow-up child clean-up task were videotaped. Principal components analyses of behaviors during the cooking task yielded two factors in mothers…

  20. Polymorphisms of Estrogen Metabolism-Related Genes and Prostate Cancer Risk in Two Populations of African Ancestry

    PubMed Central

    Emeville, Elise; Ferdinand, Séverine; Punga, Augustin; Lufuma, Simon; Blanchet, Pascal; Romana, Marc; Multigner, Luc

    2016-01-01

    Background Estrogens are thought to play a critical role in prostate carcinogenesis. It has been suggested that polymorphisms of genes encoding enzymes involved in estrogen metabolism are risk factors for prostate cancer. However, few studies have been performed on populations of African ancestry, which are known to have a high risk of prostate cancer. Objective We investigated whether functional polymorphisms of CYP17, CYP19, CYP1B1, COMT and UGT1A1 affected the risk of prostate cancer in two different populations of African ancestry. Methods In Guadeloupe (French West Indies), we compared 498 prostate cancer patients and 565 control subjects. In Kinshasa (Democratic Republic of Congo), 162 prostate cancer patients were compared with 144 controls. Gene polymorphisms were determined by the SNaPshot technique or short tandem repeat PCR analysis. Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI). Results The AA genotype and the A allele of rs4680 (COMT) appeared to be inversely associated with the risk of prostate cancer in adjusted models for both Afro-Caribbean and native African men. For the A allele, a significant inverse association was observed among cases with low-grade Gleason scores and localized clinical stage, in both populations. Conclusions These preliminary results support the hypothesis that polymorphisms of genes encoding enzymes involved in estrogen metabolism may modulate the risk of prostate cancer in populations of African ancestry. PMID:27074016

  1. African American Single Mothers: Understanding Their Lives and Families. Sage Series on Race and Ethnic Relations, Volume 10.

    ERIC Educational Resources Information Center

    Dickerson, Bette J.

    Past research on African American single mothers and their families has been conducted using conventional paradigms based upon models of the dominant culture. This practice has resulted in the creation of stereotypes and misconceptions about "the Black family." In this collection of original work by an interdisciplinary group of scholars, the…

  2. Sharing Information about Peer Relations: Parent and Adolescent Opinions and Behaviors in Hmong and African American Families

    ERIC Educational Resources Information Center

    Brown, B. Bradford; Bakken, Jeremy P.; Nguyen, Jacqueline; Von Bank, Heather G.

    2007-01-01

    Despite sharing similar attitudes regarding the information about peers that parents have a right to know, the strategies African American and Hmong families use to seek or censor information about peers diverge because of ethnic differences in emphasis on trust, nurturing autonomy, respect for parental authority, and maintaining cultural…

  3. Cultural Learning Context as It Relates to Efficacy and the Mathematics Performance of African-American Middle School Students

    ERIC Educational Resources Information Center

    Burrell, Jennifer O.

    2012-01-01

    Nearly 20 years of empirical work has demonstrated that cultural-asset focused learning environments can improve the academic performance of African-American students. One example is communal learning context, which shifts students' motivational primacy from the individual to the social group. Considering the critical role of efficacy beliefs in…

  4. Ethnic Identity in African American and European American Preadolescents: Relation to Self-Worth, Social Goals, and Aggression

    ERIC Educational Resources Information Center

    Holmes, Khiela J.; Lochman, John E.

    2009-01-01

    The current study tested models to determine the extent to which self-worth and social goals mediate the influence of ethnic identity on aggression among aggressive European and African American preadolescents. Ethnic identity emerged as important for both groups, but in different ways. Different patterns of influence of ethnic identity and of…

  5. Gender Mainstreaming in a South African Provincial Education Department: A Transformative Shift or Technical Fix for Oppressive Gender Relations?

    ERIC Educational Resources Information Center

    Karlsson, Jenni

    2010-01-01

    Although some gender activists and analysts question the efficacy of gender mainstreaming to take forward women's demands, the South African government has pursued the strategy within a number of government departments including the Department of Education. This article explores how the strategy is being implemented in one provincial education…

  6. Adiposity and hyperglycaemia in pregnancy and related health outcomes in European ethnic minorities of Asian and African origin: a review

    PubMed Central

    Jenum, Anne Karen; Sommer, Christine; Sletner, Line; Mørkrid, Kjersti; Bærug, Anne; Mosdøl, Annhild

    2013-01-01

    Background Ethnic minorities in Europe have high susceptibility to type 2 diabetes (T2DM) and, in some groups, also cardiovascular disease (CVD). Pregnancy can be considered a stress test that predicts future morbidity patterns in women and that affects future health of the child. Objective To review ethnic differences in: 1) adiposity, hyperglycaemia, and pre-eclampsia during pregnancy; 2) future risk in the mother of obesity, T2DM and CVD; and 3) prenatal development and possible influences of maternal obesity, hyperglycaemia, and pre-eclampsia on offspring's future disease risk, as relevant for ethnic minorities in Europe of Asian and African origin. Design Literature review. Results Maternal health among ethnic minorities is still sparsely documented. Higher pre-pregnant body mass index (BMI) is found in women of African and Middle Eastern descent, and lower BMI in women from East and South Asia compared with women from the majority population. Within study populations, risk of gestational diabetes mellitus (GDM) is considerably higher in many minority groups, particularly South Asians, than in the majority population. This increased risk is apparent at lower BMI and younger ages. Women of African origin have higher risk of pre-eclampsia. A GDM pregnancy implies approximately seven-fold higher risk of T2DM than normal pregnancies, and both GDM and pre-eclampsia increase later risk of CVD. Asian neonates have lower birth weights, and mostly also African neonates. This may translate into increased risks of later obesity, T2DM, and CVD. Foetal overgrowth can promote the same conditions. Breastfeeding represents a possible strategy to reduce risk of T2DM in both the mother and the child. Conclusions Ethnic minority women in Europe with Asian and African origin and their offspring seem to be at increased risk of T2DM and CVD, both currently and in the future. Pregnancy is an important window of opportunity for short and long-term disease prevention. PMID:23467680

  7. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  8. Depressive symptoms in the second trimester relate to low oxytocin levels in African-American women: a pilot study.

    PubMed

    Garfield, Lindsey; Giurgescu, Carmen; Carter, C Sue; Holditch-Davis, Diane; McFarlin, Barbara L; Schwertz, Dorie; Seng, Julia S; White-Traut, Rosemary

    2015-02-01

    Low-income African-American women report elevated prenatal depressive symptoms more often (42 %) than the national average (20 %). In the USA in 2012, 16.5 % of African-American women experienced a premature birth (less than 36 completed gestational weeks) compared to 10.3 % of white women. In addition, 13 % of African-American women had a low-birth weight infant (less than 2,500 g) compared to 7 % of white women. Variation in the neuropeptide, oxytocin has been implicated in perinatal depression, maternal behavior, regulation of stress responses, and may be associated with this health disparity. The purpose of this investigation was to examine factors associated with prenatal depressive symptoms, including plasma oxytocin levels and birth weight, in a sample of urban African-American women. Pregnant African-American women (N = 57) completed surveys and had blood drawn twice during pregnancy at 15-22 weeks and 25-37 weeks. In addition, birth data were collected from medical records. A large number of participants reported elevated prenatal depressive symptoms at the first (n = 20, 35 %) and the second (n = 19, 33 %) data points. Depressive symptoms were higher in multigravidas (t(51) = -2.374, p = 0.02), women with higher anxiety (r(47) = 0.71, p = 0.001), women who delivered their infants at an earlier gestational age (r(51) = -0.285, p = 0.04), and those without the support of the infant's father (F(4, 48) = 2.676, p = 0.04). Depressive symptoms were also higher in women with low oxytocin levels than in women with high oxytocin levels (F(2, 47) = 3.3, p = 0.05). In addition, women who had low oxytocin tended to have infants with lower birth weights (F(2, 47) = 2.9, p = 0.06). Neither prenatal depressive symptoms nor prenatal oxytocin levels were associated with premature birth. Pregnant multigravida African-American women with increased levels of anxiety and lacking the baby's father's support during the

  9. Study of phytoplankton group distribution in the NW African upwelling system and its relation with hydrographical parameters

    NASA Astrophysics Data System (ADS)

    Vega Moreno, Daura; Llerandi-García, C.; Pérez-Marrero, J.; Rueda, M. J.; Llinás, O.

    2010-05-01

    Phytoplankton is one important factor in biogeochemical cycles in the ocean, controlling partly the carbon cycle in the ocean. The CO2 captured by phytoplankton in shallow waters is transported to deeper layers in the ocean (Anderson, 2005). This only happens when microplankton or nanoplankton is formed due to their bigger size contributes their sinking to deeper layers. In the case of picoplankton the carbon is recycled in the same zone where is produced. The type of phytoplankton predominant can vary according to hydrographical and chemical properties present (Jeffrey et al., 2005). Pigment speciation can provide valuable ecological information in the form of classification of phytoplanktonic biomass in different groups (chlorophyta, diatoms, dinoflagellates, coccolithophorids or silicoflagellates) organized in different sizes: microphytoplankton (20-200 µm), nanophytoplankton (2-20 µm) and picophytoplankton (0.2-2 µm). There are different data processing methodologies for obtaining these classifications, one of the most accepted is the procedure taken by NASA (Hooker et al., 2005) developed by Vidussi et al. (2001), and also the use of CHEMTAX program (Mackey, 1996). It was studied pigment composition of phytoplankton and several physical and chemical properties, focused in the Northwestern African Upwelling area, including Senegal area, Mauritanian and Cape Blanc area and Morroco area. Pigment composition was analyzed by high pressure liquid chromatography and determined in different samples in the studied area, with this composition it was obtained phytoplankton classification, according to their size and to the different phytoplankton groups. These results have been related with marine biogeochemical factors presents in studied zone. References: - Anderson, T. Plankton functional type modelling: running before we can walk? Journal of Plankton Research, 2005, 27, 1073-7081 - Hooker, S.; Heukelem, L.; Thomas, C.; Claustre, H.; Ras, J.; Barlow, R.; Sessions

  10. Fault-related Soil Efflux of Mantle-derived CO2 in the Magadi and Natron Basins, East African Rift

    NASA Astrophysics Data System (ADS)

    Lee, H.; Muirhead, J.; Fischer, T. P.; Kattenhorn, S. A.; Ebinger, C. J.; Thomas, N.; Kianji, G.; Onguso, B.; Maqway, M. D.

    2014-12-01

    The Magadi (Kenya) and Natron (Tanzania) basins of the East African Rift are in an early stage (< 7 Ma) of continental rifting. The many normal faults observed in these areas create sediment-filled basins and a large number of alkaline springs feed water into two major lakes (Lake Magadi and Natron). Earthquake swarms reported in 1998 (Magadi) and 2007 (Natron) were accompanied by surface ruptures. Although CO2 is a major component of magmatic volatiles and fault-related fluids that may facilitate earthquakes and fault weakening, the soil CO2 efflux of continental rifts is poorly known. Here, we report soil CO2 flux rates measured in the Magadi and Natron basins, and carbon isotope values (δ13C, ‰ vs. PDB) to constrain CO2sources. Soil CO2 fluxes were measured at fault zones, horsts, grabens, and surface ruptures by EGM-4 (PP systems) with a gas accumulation chamber. A t-shaped connector with a needle was used for gas sampling into evacuated glass vials with a rubber septum. δ13C values were measured by isotope ratio mass spectrometer with a gas bench at the stable isotope laboratory, University of New Mexico. The fault zones in the Magadi basin have higher maximum CO2 flux rates (< 533.52 g m-2 d-1) and heavier δ13C values (< -3.8 ‰) than the Natron basin (< 147.12 g m-2 d-1 and < -6.2 ‰, respectively). In both areas, soil CO2 efflux is insignificant (< 10 g m-2 d-1) in both horsts and the middle of grabens with lighter δ 13C values (~ -10 ‰) likely resulting from significant air contribution. The highest CO2 flux rates (< 919.44 g m-2 d-1) were measured at recent surface ruptures, but they have lighter δ13C values (-10 to -15 ‰), implying significant air and biogenic C contributions. Our results indicate that (1) normal faults are pathways that deliver mantle-derived CO2 to the surface, (2) the Magadi basin exhibits greater mantle-derived CO2 than the Natron basin, and (3) recent ruptures are zones of shallow CO2 degassing.

  11. Charts relating the compressive buckling stress of longitudinally supported plates to the effective deflectional and rotational stiffness of the supports

    NASA Technical Reports Server (NTRS)

    Anderson, Roger A; Semonian, Joseph W

    1954-01-01

    A stability analysis is made of a long flat rectangular plate subjected to a uniform longitudinal compressive stress and supported along its longitudinal edges and along one or more longitudinal lines by elastic line supports. The elastic supports possess deflectional and rotational stiffness. Such configuration is an idealization of the compression cover skin and internal structure of a wing and tail surfaces. The results of the analysis are presented in the form of charts in which the buckling-stress coefficient is plotted against the buckle length of the plate for a wide range of support stiffnesses. The charts make possible the determination of the compressive buckling stress of plates supported by members whose stiffness may or may not be defined by elementary beam bending and twisting theory but yet whose effective restraint is amenable to evaluation. The deflectional and rotational stiffness provided by longitudinal stiffeners and full-depth webs is discussed and numerical examples are given to illustrate the application of the charts to the design of wing structures.

  12. IGF-I and IGFBP-3 polymorphisms in relation to circulating levels among African American and Caucasian women

    PubMed Central

    D’Aloisio, Aimee A.; Schroeder, Jane C.; North, Kari E.; Poole, Charles; West, Suzanne L.; Travlos, Gregory S.; Baird, Donna D.

    2010-01-01

    Circulating insulin-like growth factor-one (IGF-I) and IGF binding protein-3 (IGFBP-3) levels have been associated with common diseases. Although family-based studies suggest that genetic variation contributes to circulating IGF-I and IGFBP-3 levels, analyses of associations with multiple IGF-I and IGFBP-3 single nucleotide polymorphisms (SNPs) have been limited, especially among African Americans. We evaluated 30 IGF-I and 15 IGFBP-3 SNPs and estimated diplotypes in association with plasma IGF-I and IGFBP-3 among 984 premenopausal African American and Caucasian women. In both races, IGFBP-3 rs2854746 (Ala32Gly) was positively associated with plasma IGFBP-3 (CC versus GG mean difference among Caucasians = 631 ng/ml, 95% confidence interval: 398, 864; African Americans = 897 ng/ml, 95% confidence interval: 656, 1138), and IGFBP-3 diplotypes with the rs2854746 GG genotype had lower mean IGFBP-3 levels than referent diplotypes with the CG genotype, while IGFBP-3 diplotypes with the CC genotype had higher mean IGFBP-3 levels. IGFBP-3 rs2854744 (−202 A/C) was in strong linkage disequilibrium with rs2854746 in Caucasians only, but was associated with plasma IGFBP-3 in both races. Eight additional IGFBP-3 SNPs were associated with 5% or greater differences in mean IGFBP-3 levels, with generally consistent associations between races. Twelve IGF-I SNPs were associated with 10% or greater differences in mean IGF-I levels, but associations were generally discordant between races. Diplotype associations with plasma IGF-I did not parallel IGF-I SNP associations. Our study supports that common IGFBP-3 SNPs, especially rs2854746, influence plasma IGFBP-3 levels among African Americans and Caucasians, but provides less evidence that IGF-I SNPs affect plasma IGF-I levels. PMID:19240240

  13. Making sense of HIV testing: social representations in young Africans' HIV-related narratives from six countries.

    PubMed

    Beres, Laura K; Winskell, Kate; Neri, Elizabeth M; Mbakwem, Benjamin; Obyerodhyambo, Oby

    2013-01-01

    HIV testing and counselling are a critical intervention to support treatment access and prevent new infections. Despite high rates of infection, few young Africans know their HIV status. With the aim of informing initiatives that encourage HIV testing and access to testing benefits, this study seeks to understand how young Africans make sense of HIV testing. We conducted thematic narrative-based analysis of a stratified random sample (n = 586, ≈ 5%) from 11,354 narratives written in 2005 by males and females aged 10-24 from six sub-Saharan African countries for the 'Scenarios from Africa' scriptwriting contest which invites young people to contribute ideas for short films about HIV. The factors represented by the young authors as influencing testing behaviour and outcomes are complex and interactive, indicating that interventions that are not contextually appropriate are unlikely to affect a shift towards increased testing or improved post-testing outcomes. The narratives point to opportunities to increase HIV testing in this demographic. PMID:24004339

  14. Focusing of relative plate motion at a continental transform fault: Cenozoic dextral displacement >700 km on New Zealand's Alpine Fault, reversing >225 km of Late Cretaceous sinistral motion

    NASA Astrophysics Data System (ADS)

    Lamb, Simon; Mortimer, Nick; Smith, Euan; Turner, Gillian

    2016-03-01

    The widely accepted ˜450 km Cenozoic dextral strike-slip displacement on New Zealand's Alpine Fault is large for continental strike-slip faults, but it is still less than 60% of the Cenozoic relative plate motion between the Australian and Pacific plates through Zealandia, with the remaining motion assumed to be taken up by rotation and displacement on other faults in a zone up to 300 km wide. We show here that the 450 km total displacement across the Alpine Fault is an artifact of assumptions about the geometry of New Zealand's basement terranes in the Eocene, and the actual Cenozoic dextral displacement across the active trace is greater than 665 km, with more than 700 km (and <785 km since 25 Ma) occurring in a narrow zone less than 10 km wide. This way, the Alpine Fault has accommodated almost all (>94%) of the relative plate motion in the last 25 Ma at an average rate in excess of 28 mm/yr. It reverses more than 225 km (and <300 km) of sinistral shear through Zealandia in the Late Cretaceous, when Zealandia lay on the margin of Gondwana, providing a direct constraint on the kinematics of extension between East and West Antarctica at this time.

  15. Slab dragging and the recent geodynamic evolution of the western Mediterranean plate boundary region

    NASA Astrophysics Data System (ADS)

    Spakman, Wim; Chertova, Maria V.; van den Berg, Arie P.; Thieulot, Cedric; van Hinsbergen, Douwe J. J.

    2016-04-01

    The Tortonian-Present geodynamic evolution of the plate boundary between North Africa and Iberia is characterized by first-order enigmas. This concerns, e.g., the diffuse tectonic activity of the plate boundary; the crustal thickening below the Rif; the closing of the northern Moroccan marine gateways prior to the Messinian Salinity Crisis; crustal extension of the central to eastern Betics; the origin and sense of motion of the large left-lateral Trans Alboran Shear Zone (TASZ) and Eastern Betic Shear Zone (EBSZ); and lithosphere delamination of the North African continental edge. Many explanations have been given for each of these seemingly disparate tectonic features, which invariably have been addressed in the plate tectonic context of the NW-SE relative plate convergence between the major plates since the Tortonian, mostly independently from each other. Usually there is no clear role for the subducted slab underlying the region, except for presumed rollback, either to SW or to the W, depending on the type of observations that require explanation. Here we integrate the dynamic role of the slab with the NW-SE relative plate convergence by 3-D numerical modelling of the slab evolution constrained by absolute plate motions (Chertova et al., JGR,2014 & Gcubed 2014). By combining observations and predictions from seismology, geology, and geodesy, with our numerical 3-D slab-mantle dynamics modelling, we developed a new and promising geodynamic framework that provides explanations of all noted tectonic enigmas in a coherent and connected way. From the Tortonian until today, we propose that mantle-resisted slab dragging combines with the NW-SE plate convergence across the (largely) unbroken plate boundary to drive the crustal deformation of the region. Slab dragging is the lateral transport, pushing or pulling, of slab through the mantle by the absolute motion of the subducting plate (Chertova et al., Gcubed, 2014). Because the slab is connected to both the Iberian

  16. The Development and Evaluation of a Portion Plate for Youth: A Pilot Study

    ERIC Educational Resources Information Center

    Bohnert, Amy M.; Randall, Edin T.; Tharp, Stephanie; Germann, Julie

    2011-01-01

    Objective: To develop and evaluate a portion plate for adolescents (Nutri-plate). Methods: Sixteen African American adolescents (mean age = 12.94 years; 66% male) were randomized to participate in either plate design or nutrition education sessions. Adolescents' input was used to create the Nutri-plate, and participants' food selection and intake…

  17. Extraordinary high ductility/strength of the interface designed bulk W-ZrC alloy plate at relatively low temperature

    PubMed Central

    Xie, Z. M.; Liu, R.; Miao, S.; Yang, X. D.; Zhang, T.; Wang, X. P.; Fang, Q. F.; Liu, C. S.; Luo, G. N.; Lian, Y. Y.; Liu, X.

    2015-01-01

    The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m2 thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength. PMID:26531172

  18. Extraordinary high ductility/strength of the interface designed bulk W-ZrC alloy plate at relatively low temperature

    NASA Astrophysics Data System (ADS)

    Xie, Z. M.; Liu, R.; Miao, S.; Yang, X. D.; Zhang, T.; Wang, X. P.; Fang, Q. F.; Liu, C. S.; Luo, G. N.; Lian, Y. Y.; Liu, X.

    2015-11-01

    The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m2 thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength.

  19. The interpretation of crustal dynamics data in terms of plate interactions and active tectonics of the Anatolian plate and surrounding regions in the Middle East

    NASA Technical Reports Server (NTRS)

    Toksoz, M. Nafi; Reilinger, Robert

    1992-01-01

    A detailed study was made of the consequences of the Arabian plate convergence against Eurasia and its effects on the tectonics of Anatolia and surrounding regions of the eastern Mediterranean. A primary source of information is time rates of change of baseline lengths and relative heights determined by repeated SLR measurements. These SLR observations are augmented by a network of GPS stations in Anatolia, Aegea, and Greece, established and twice surveyed since 1988. The existing SLR and GPS networks provide the spatial resolution necessary to reveal the details of ongoing tectonic processes in this area of continental collision. The effort has involved examining the state of stress in the lithosphere and relative plate motions as revealed by these space based geodetic measurements, seismicity, and earthquake mechanisms as well as the aseismic deformations of the plates from conventional geodetic data and geological evidence. These observations are used to constrain theoretical calculations of the relative effects of: (1) the push of the Arabian plate; (2) high topography of Eastern Anatolia; (3) the geometry and properties of African-Eurasian plate boundary; (4) subduction under the Hellenic Arc and southwestern Turkey; and (5) internal deformation and rotation of the Anatolian plate.

  20. Social integration and suicide-related ideation from a social network perspective: a longitudinal study among inner-city African Americans.

    PubMed

    Kuramoto, S Janet; Wilcox, Holly C; Latkin, Carl A

    2013-08-01

    Social network density, as measured by the extent to which network members know each other, was examined to determine whether it is associated with suicide-related ideation and plan approximately 3 years later. Eight hundred and nineteen African Americans were interviewed at Wave 1 (1997-1999) and Wave 4 (2001-2003) of the Self-Help In Eliminating Life-Threatening Diseases (SHIELD) study, a HIV preventive intervention study in Baltimore, MD. Multinomial logistic regression models were used to compare risks of suicide-related ideation and plan at Wave 4 by Wave 1 density. Even after adjusting for baseline sociodemographic characteristics and depressive symptoms, individuals with a lower level of density were three times more likely to report suicide-related ideation and plan in the past year at Wave 4. The findings reinforce the importance of social integration among inner-city African Americans from a social network perspective. Future research should examine the mechanisms associated with this relationship and other social network constructs. PMID:23530665

  1. Peen plating

    NASA Technical Reports Server (NTRS)

    Babecki, A. J. (Inventor); Haehner, C. L.

    1973-01-01

    A process for metal plating which comprises spraying a mixture of metallic powder and small peening particles at high velocity against a surface is described. The velocity must be sufficient to impact and bond metallic powder onto the surface. In the case of metal surfaces, the process has as one of its advantages providing mechanical working (hardening) of the surface simultaneously with the metal plating.

  2. Correlation between plate motions and tectonic subsidence of sedimentary basins in Africa

    SciTech Connect

    Janssen, M.E. )

    1993-09-01

    From the early Mesozoic until the Holocene, the African continent was generally in a state of extension, based on plate tectonic reconstructions and sedimentary basin subsidence studies. Beginning with the breakup of Gondwana in the Permian-Triassic, this resulted in the formation of the present-day African continental margins and a series of intracontinental rift basins, located mainly on older (late Proterozoic) shear zones. Numerous wells from marginal, as well as intracontinental rift basins, have been backstripped to elucidate their Mesozoic and Tertiary tectonic histories. They show a generally consistent patterns of subsidence and uplift phases in all basins. During the evolution of these basins, the direction of African plate motion changed several times. This was related to the differential opening of the central and south Atlantic oceans, changes in spreading rates in both the Atlantic and Indian oceans, and the collision between Africa and Europe. Episodes of compressional deformation related to these plate tectonic changes are revealed in backstripped tectonic subsidence curves.

  3. Lohse's historic plate archive

    NASA Astrophysics Data System (ADS)

    Tsvetkov, M.; Tsvetkova, K.; Richter, G.; Scholz, G.; Böhm, P.

    The description and the analysis of Oswald Lohse's astrophotographic plates, collected at the Astrophysical Observatory Potsdam in the period 1879 - 1889, are presented. 67 plates of the archive, taken with the greatest instrument of the observatory at that time - the refractor (D = 0.30 m, F = 5.40 m, scale = 38''/mm) and with the second heliographic objective (D = 0.13 m, F = 1.36 m, scale = 152''/mm) - - survived two world wars in relative good condition. The plate emulsions are from different manufacturers in the beginning of astrophotography (Gädicke, Schleussner, Beernaert, etc.). The sizes of the plates are usually 9x12 cm2, which corresponds to fields of 1.2deg and 5deg respectively for each instrument mentioned above. The average limiting magnitude is 13.0(pg). Besides of the plates received for technical experiments (work on photographic processes, testing of new instruments and methods of observations), the scientific observations follow programs for studies of planet surfaces, bright stars, some double stars, stellar clusters and nebulous objects. Lohse's archive is included into the Wide Field Plate Database (http://www.skyarchive.org) as the oldest systematic one, covering the fields of Orion (M42/43), Pleiades, h & chi Persei, M37, M3, M11, M13, M92, M31, etc. With the PDS 2020 GM+ microdensitometer of Münster University 10 archive plates were digitized.

  4. An Introduction to West African Literature.

    ERIC Educational Resources Information Center

    Taiwo, Oladele

    Intended to provide help for those interested in studying West African literature, this book is divided into three parts. Part One provides background information: the various African oral traditions are discussed, related to the way of life of the people, and examined for the extent to which they form the basis of present West African literary…

  5. Relation of clinical, echocardiographic and electrocardiographic features of cardiac amyloidosis to the presence of the transthyretin V122I allele in older African-American men.

    PubMed

    Jacobson, Daniel; Tagoe, Clement; Schwartzbard, Arthur; Shah, Alan; Koziol, James; Buxbaum, Joel

    2011-08-01

    Previous studies have shown that 3% to 4% of African Americans carry an amyloidogenic allele of the human serum protein transthyretin (TTR V122I). The allele appears to have an absolute anatomic risk for cardiac amyloid deposition after 65 years of age. In this study, a case-control comparison was performed of clinical, echocardiographic, and electrocardiographic characteristics of 23 age at risk carriers of the amyloidogenic allele and 46 age-, gender-, and ethnically matched noncarriers being evaluated for cardiac disease using standard clinical testing. The 2 groups were matched for blood pressure and the cardiac ejection fraction. None of the subjects had a prestudy diagnosis of cardiac amyloidosis. Carriers of the amyloidogenic allele were found to have statistically significant increases in the occurrence of many of the echocardiographic features of cardiac amyloidosis relative to the noncarriers and a higher frequency of congestive heart failure and atrial fibrillation. The observations suggest that TTR V122I represents a substantial risk for clinically significant cardiac amyloidosis in elderly African American men, behaving as an age-dependent autosomal dominant disease-associated allele. The diagnosis is difficult to make but can be suspected in African Americans aged >60 years on the basis of age, echocardiographic evidence of diastolic dysfunction, and interventricular septal thickening, even in the absence of more recently available sophisticated echocardiographic techniques for evaluating long-axis function and cardiac magnetic resonance imaging. Positive results for the amyloidogenic TTR V122I allele support the diagnosis and define the origin of the disease, which can be confirmed by endomyocardial biopsy. PMID:21600538

  6. REDUCED GLUTEAL EXPRESSION OF ADIPOGENIC AND LIPOGENIC GENES IN BLACK SOUTH AFRICAN WOMEN IS ASSOCIATED WITH OBESITY-RELATED INSULIN RESISTANCE

    PubMed Central

    Goedecke, Julia H.; Evans, Juliet; Keswell, Dheshnie; Stimson, Roland H.; Livingstone, Dawn E.W.; Hayes, Philip; Adams, Kevin; Dave, Joel A.; Victor, Hendriena; Levitt, Naomi S.; Lambert, Estelle V.; Walker, Brian R.; Seckl, Jonathan R.; Olsson, Tommy; Kahn, Steven E.

    2014-01-01

    Context Black South African women are less insulin sensitive than their white counterparts, despite less central and greater peripheral fat deposition. We hypothesized that this paradox may be explained, in part, by differences in the adipogenic capacity of subcutaneous adipose tissue (SAT). Objective To measure adipogenic and lipogenic gene expression in abdominal and gluteal SAT depots, and determine their relationships with insulin sensitivity (SI) in South African women. Design Cross-sectional. Participants 14 normal-weight (BMI <25 kg/m2) black, 13 normal-weight white, 14 obese (BMI >30 kg/m2) black and 13 obese white premenopausal South African women. Main outcomes SI (frequently sampled intravenous glucose tolerance test) in relation to expression of adipogenic and lipogenic genes in abdominal and gluteal SAT depots. Results With increasing BMI, black women had less visceral fat (P=0.03) and more abdominal (P=0.017) and gynoid (P=0.041) SAT but had lower SI (P<0.01) than white women. The expression of adipogenic and lipogenic genes was proportionately lower with obesity in black, but not white women in the gluteal and deep SAT depots (P<0.05 for ethnicity x BMI effect). In black women only, the expression of these genes correlated positively with SI (all P<0.05), independently of age and fat mass. Conclusions Obese black women have reduced SAT expression of adipogenic and lipogenic genes compared to white women, which associates with reduced SI. These findings suggest that obesity in black women impairs SAT adipogenesis and storage, potentially leading to insulin resistance and increased risk of type 2 diabetes. PMID:21956425

  7. Relative humidity effects on the surface electrical properties of resistive plate chamber melaminic laminates uncoated and coated with polymerized linseed oil film

    SciTech Connect

    Bearzotti, Andrea; Palummo, Lucrezia

    2007-09-15

    Relative humidity is an important quantity to control in many manufacturing environments such as semiconductor industry. Humidity and moisture can affect many electronic devices, generally rendering their operation worse. In this study we present results showing that in some specific applications, humidity can improve the performance of an electronic device. Resistive plate chambers are used as trigger detectors of the muon system in LHC (large hadron collider) experiments ATLAS (a toroidal LHC apparatus), CMS (compact muon solenoid) and ALICE (a large ion collider experiment) and as detector in cosmic rays experiment ARGO (astrophysical radiation with ground-based observatory). These detectors are made of phenolic-melaminic laminate electrodes, coated with a polymerized linseed oil film delimiting the gaseous sensitive volume. The loss of some of the detector capability can be progressive in time and due to the intrinsic limits of the detector materials. One of these effects is due to an increase of the total plate resistance, that is correlated to ion migration and relativity humidity phenomena. Our purpose is to understand the relative humidity (RH) influence on the conduction mechanisms on the electrodes surface. Results of amperometric measurements on laminate samples kept at a fixed temperature of 22 deg. C, cycling RH between 10% and 90% are here presented.

  8. Mantle support of the East African Rift System

    NASA Astrophysics Data System (ADS)

    Lin, S.; van Keken, P. E.; Brandenburg, J. P.; Furman, T.; Bryce, J.

    2007-12-01

    The African Superplume is a region of slow seismic wave velocities in the lower mantle under southern Africa. The uplift, volcanism and rifting that defines the much of eastern and southern Africa suggest a dynamic link between lower mantle dynamics and near-surface processes affecting the African plate. The dynamic link between the lower mantle and the surface, and the structure and dynamics of the upper mantle below the East African Rift System (EARS) remain unclear. As part of a comprehensive geochemical and numerical investigation of basaltic magmatism in the EARS we have modeled the interaction between putative upper mantle plumes and the rifting continental lithosphere. The modeling provides dynamically tested scenarios that explain the observed episodes of Cenozoic volcanism. Results from recent models that provided an explanation for the present day distribution of volcanism (Lin et al., EPSL, 237, 2005) suggest two plumes below Afar and Tanzania whose uplift is influenced by lithospheric topography. In new 3D modeling we provide improved quantification of the mantle involvement in generating EARS volcanism as constrained by the timing of uplift and regional volcanism. The time scales of episodicity of the volcanism observed at Turkana (related to the Tanzania-Kenya plume) since 45 Ma can be explained by deep- seated time-dependent plume activity. We suggest that this time-dependence is due to thermochemical interactions of dense recycled oceanic crust in the thermally hot regions in the African superplume region (Lin and Van Keken, Nature, 436, 2005).

  9. Caribbean plate interactions

    SciTech Connect

    Ball, M. )

    1993-02-01

    Vector analysis of plate motions, derived from studies of Atlantic magnetic lineations and fracture zone trends, indicates the following relative movements between the Caribbean, North American, and South American Plates. (1) During Early Jurassic to Early Cretaceous, the North American Plate moved 1900 km westward and 900 km northward relative to the South American Plate. A broad zone including the Caribbean region, i.e., the zone between the North and South America Plates, was a site of left-lateral shear and north-south extension. (2) During Early Cretaceous to Late Cretaceous, the North American Mate moved an additional 1200 km westward relative to South America across this zone. (3) During Late Cretaceous to the end of the Eocene, the North American Plate moved 200 km westward and 400 km northward relative to the South American Plate. (4) From the end of the Eocene to near the end of the Miocene, North America converged on South America some 200 km and moved 100 km eastward relative to it. Through the Mesozoic and earliest Tertiary history of the Caribbean, the region was a shear zone within which left-lateral displacement exceeded 3000 km and north-south extension exceeded 1300 km. In regard to time, 80% of the history of the Caribbean region is one of north-south extension and left-lateral shear. In terms of space, 97% of the shear is left-lateral and the ratio of divergence versus convergence is 7 to 1. Thus, characterizing the Caribbean region, and the Atlantic to its east, as a zone of north-south extension and left-lateral shear, is a fair generalization.

  10. Violin plate modes.

    PubMed

    Gough, Colin

    2015-01-01

    As the first step toward developing a generic model for the acoustically radiating vibrational modes of the violin and related instruments, the modes of both freely supported and edge-constrained top and back plates have been investigated as functions of shape, arching height, elastic anisotropy, the f-holes and associated island area, thickness graduations, and the additional boundary constraints of the ribs, soundpost, and bass-bar present in the assembled instrument. Comsol shell structure finite element software has been used as a quasi-experimental tool, with physical and geometric properties varied smoothly, often over several orders of magnitude, allowing the development of the plate modes to be followed continuously from those of an initially square plate to those of doubly-arched, guitar-shaped, orthotropic plates and their dependence on all the above factors. PMID:25618046

  11. Bibliometric Assessment of European and Sub-Saharan African Research Output on Poverty-Related and Neglected Infectious Diseases from 2003 to 2011

    PubMed Central

    Gurney, Karen A.; Mgone, Charles S.

    2015-01-01

    Background The European & Developing Countries Clinical Trials Partnership (EDCTP) is a partnership of European and sub-Saharan African countries that aims to accelerate the development of medical interventions against poverty-related diseases (PRDs). A bibliometric analysis was conducted to 1) measure research output from European and African researchers on PRDs, 2) describe collaboration patterns, and 3) assess the citation impact of clinical research funded by EDCTP. Methodology/Principal Findings Disease-specific research publications were identified in Thomson Reuters Web of Science using search terms in titles, abstracts and keywords. Publication data, including citation counts, were extracted for 2003–2011. Analyses including output, share of global papers, normalised citation impact (NCI), and geographical distribution are presented. Data are presented as five-year moving averages. European EDCTP member countries accounted for ~33% of global research output in PRDs and sub-Saharan African countries for ~10% (2007–2011). Both regions contributed more to the global research output in malaria (43.4% and 22.2%, respectively). The overall number of PRD papers from sub-Saharan Africa increased markedly (>47%) since 2003, particularly for HIV/AIDS (102%) and tuberculosis (TB) (81%), and principally involving Southern and East Africa. For 2007–2011, European and sub-Saharan African research collaboration on PRDs was highly cited compared with the world average (NCI in brackets): HIV/AIDS 1.62 (NCI: 1.16), TB 2.11 (NCI: 1.06), malaria 1.81 (NCI: 1.22), and neglected infectious diseases 1.34 (NCI: 0.97). The NCI of EDCTP-funded papers for 2003–2011 was exceptionally high for HIV/AIDS (3.24), TB (4.08) and HIV/TB co-infection (5.10) compared with global research benchmarks (1.14, 1.05 and 1.35, respectively). Conclusions The volume and citation impact of papers from sub-Saharan Africa has increased since 2003, as has collaborative research between Europe and

  12. Making sense of condoms: social representations in young people’s HIV-related narratives from six African countries

    PubMed Central

    Winskell, Kate; Obyerodhyambo, Oby; Stephenson, Rob

    2011-01-01

    Condoms are an essential component of comprehensive efforts to control the HIV epidemic, both for those who know their status and for those who do not. Although young people account for almost half of all new HIV infections, reported condom use among them remains low in many sub-Saharan African countries. In order to inform education and communication efforts to increase condom use, we examined social representations of condoms among young people aged 10–24 in six African countries/regions with diverse HIV prevalence rates: Swaziland, Namibia, Kenya, South-East Nigeria, Burkina Faso, and Senegal. We used a unique data source, namely 11,354 creative ideas contributed from these countries to a continent-wide scriptwriting contest, held from 1st February to 15th April 2005, on the theme of HIV/AIDS. We stratified each country sample by the sex, age (10–14, 15–19, 20–24), and urban/rural location of the author and randomly selected up to 10 narratives for each of the 12 resulting strata, netting a total sample of 586 texts for the six countries. We analyzed the narratives qualitatively using thematic data analysis and narrative-based methodologies. Differences were observed across settings in the prominence accorded to condoms, the assessment of their effectiveness, and certain barriers to and facilitators of their use. Moralization emerged as a key impediment to positive representations of condoms, while humour was an appealing means to normalize them. The social representations in the narratives identify communication needs in and across settings and provide youth-focused ideas and perspectives to inform future intervention efforts. PMID:21388731

  13. Making sense of condoms: social representations in young people's HIV-related narratives from six African countries.

    PubMed

    Winskell, Kate; Obyerodhyambo, Oby; Stephenson, Rob

    2011-03-01

    Condoms are an essential component of comprehensive efforts to control the HIV epidemic, both for those who know their status and for those who do not. Although young people account for almost half of all new HIV infections, reported condom use among them remains low in many sub-Saharan African countries. In order to inform education and communication efforts to increase condom use, we examined social representations of condoms among young people aged 10-24 in six African countries/regions with diverse HIV prevalence rates: Swaziland, Namibia, Kenya, South-East Nigeria, Burkina Faso, and Senegal. We used a unique data source, namely 11,354 creative ideas contributed from these countries to a continent-wide scriptwriting contest, held from 1(st) February to 15(th) April 2005, on the theme of HIV/AIDS. We stratified each country sample by the sex, age (10-14, 15-19, 20-24), and urban/rural location of the author and randomly selected up to 10 narratives for each of the 12 resulting strata, netting a total sample of 586 texts for the six countries. We analyzed the narratives qualitatively using thematic data analysis and narrative-based methodologies. Differences were observed across settings in the prominence accorded to condoms, the assessment of their effectiveness, and certain barriers to and facilitators of their use. Moralization emerged as a key impediment to positive representations of condoms, while humour was an appealing means to normalize them. The social representations in the narratives identify communication needs in and across settings and provide youth-focused ideas and perspectives to inform future intervention efforts. PMID:21388731

  14. Evolutionary plasticity in coccidia - striking morphological similarity of unrelated coccidia (apicomplexa) from related hosts: Eimeria spp. from African and Asian Pangolins (Mammalia: Pholidota).

    PubMed

    Jirků, Miloslav; Kvičerová, Jana; Modrý, David; Hypša, Václav

    2013-07-01

    Two morphologically similar, but phylogenetically unrelated Eimeria species from ancient mammals, African Tree Pangolin Phataginus tricuspis and Sunda Pangolin Manis javanica (Pholidota: Manidae), from two distant biogeographic realms (Afrotropical and Oriental), are characterized and compared morphologically and molecularly. Phylogenetic analyses produced an unstable topology. However, while precise position of the two Eimeria species from pangolins could not be firmly established due to the lack of related taxa, it is evident that they are not closely related and do not fall into any of the so far recognized eimerian lineages. Moreover, an eimerian found in P. tricuspis is described as a new species Eimeria nkaka n. sp., based on morphology of oocysts, endogenous developmental stages and sequence data. PMID:23837921

  15. Preventing HIV among Latino and African American Gay and Bisexual Men in a Context of HIV-Related Stigma, Discrimination, and Homophobia: Perspectives of Providers

    PubMed Central

    Brooks, Ronald A.; Etzel, Mark A.; Hinojos, Ernesto; Henry, Charles L.; Perez, Mario

    2005-01-01

    HIV-related stigma, discrimination, and homophobia impede community based efforts to combat HIV disease among Latino and African American gay and bisexual men. This commentary highlights ways to address these social biases in communities of color in Los Angeles from the perspectives of staff from HIV prevention programs. Information was collected from HIV prevention program staff participating in a two-day symposium. The outcomes from the symposium offer strategies for developing and implementing HIV prevention services for Latino and African American gay and bisexual men, which include: 1) addressing social biases present in a community that can hinder, and even prohibit, utilization of effective HIV prevention programs; 2) recasting HIV prevention messages in a broader social or health context; 3) developing culturally appropriate HIV prevention messages; 4) exploring new modalities and venues for delivering HIV prevention messages that are appropriate for gay and bisexual men of color and the communities in which they live; and 5) broadening the target of HIV prevention services to include service providers, local institutions and agencies, and the community at-large. These strategies underscore the need to consider the social and contextual factors of a community when designing and implementing HIV prevention programs. PMID:16283834

  16. Oncology pharmacy units: a safety policy for handling hazardous drugs and related waste in low- and middle-income African countries—Angolan experience

    PubMed Central

    da Conceição, Ana Vaz; Bernardo, Dora; Lopes, Lygia Vieira; Miguel, Fernando; Bessa, Fernanda; Monteiro, Fernando; Santos, Cristina; Oliveira, Blasques; Santos, Lúcio Lara

    2015-01-01

    In African countries, higher rates of late-stage cancers at the time of first diagnosis are a reality. In this context, hazardous drugs (HDs), such as chemotherapy, play an important role and have immense benefits for patients’ treatment. HDs should be handled under specific conditions. At least a class 5 environment primary engineering control (PEC), physically located in an appropriate buffer area, is mandatory for sterile HDs compounding, as well as administrative control, personal protective equipment, work practices and other engineering and environmental controls, in order to protect the environment, patient, and worker. The aim of this study is to describe the Angolan experience regarding the development of oncology pharmacy units and discuss international evidence-based guidelines on handling HDs and related waste. Measures to incorporate modern and economical solutions to upgrade or build adequate and safe facilities and staff training, in order to comply with international guidelines in this area, are crucial tasks for African countries of low and middle income. PMID:26557873

  17. The relative role of ocean-atmosphere interaction and African easterly waves in the generation and development of Tropical cyclones in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Cabos, William; Sein, Dmitry; Hodges, Kevin; Jacob, Daniela

    2016-04-01

    We use the regionally coupled ocean - atmosphere model ROM and its atmospheric component REMO in standalone configuration in order to assess the relative role of ocean feedbacks and the African easterly waves in the simulation of tropical cyclonic activity in the Atlantic ocean. To this end, a number of coupled and uncoupled simulations forced by ERA-Interim boundary conditions have been carried out. In one set of simulations, the atmospheric domain includes the Northern Africa land masses, where the easterly waves are formed. In a second set of simulations, the easterly waves are taken from the ERA Interim reanalysis, as atmospheric domain excludes explicitly the African land masses. We study the statistics of modeled tracks of the tropical cyclones in the simulations. We found that the coupling has a strong impact on the number of tropical cyclones generated in the Northern Tropical Atlantic. In the coupled run it was close to the observations, while in the uncoupled runs the number of tropical cyclones was strongly overestimated. The coupling also influences the simulated position of the ITCZ.

  18. Convective Removal of Continental Margin Lithosphere at the Edges of Subducting Oceanic Plates

    NASA Astrophysics Data System (ADS)

    Levander, A.; Bezada, M. J.; Palomeras, I.; Masy, J.; Humphreys, E.; Niu, F.

    2013-12-01

    Although oceanic lithosphere is continuously recycled to the deeper mantle by subduction, the rates and manner in which different types of continental lithospheric mantle are recycled is unclear. Cratonic mantle can be chemically reworked and essentially decratonized, although the frequency of decratonization is unclear. Lithospheric mantle under or adjacent to orogenic belts can be lost to the deeper mantle by convective downwellings and delamination phenomena. Here we describe how subduction related processes at the edges of oceanic plates adjacent to passive continental margins removes the mantle lithosphere from beneath the margin and from the continental interior. This appears to be a widespread means of recycling non-cratonic continental mantle. Lithospheric removal requires the edge of a subducting oceanic plate to be at a relatively high angle to an adjacent passive continental margin. From Rayleigh wave and body wave tomography, and receiver function images from the BOLIVAR and PICASSO experiments, we infer large-scale removal of continental margin lithospheric mantle from beneath 1) the northern South American plate margin due to Atlantic subduction, and 2) the Iberian and North African margins due to Alboran plate subduction. In both cases lithospheric mantle appears to have been removed several hundred kilometers inland from the subduction zones. This type of ';plate-edge' tectonics either accompanies or pre-conditions continental margins for orogenic activity by thinning and weakening the lithosphere. These processes show the importance of relatively small convective structures, i.e. small subducting plates, in formation of orogenic belts.

  19. The effects of a mass media HIV-risk reduction strategy on HIV-related stigma and knowledge among African American adolescents.

    PubMed

    Kerr, Jelani C; Valois, Robert F; DiClemente, Ralph J; Carey, Michael P; Stanton, Bonita; Romer, Daniel; Fletcher, Faith; Farber, Naomi; Brown, Larry K; Vanable, Peter A; Salazar, Laura F; Juzang, Ivan; Fortune, Thierry

    2015-03-01

    HIV-related stigma undermines HIV prevention, testing, and treatment. Multipronged risk-reduction strategies may reduce stigma among African American adolescents. To test the effectiveness of a risk-reduction strategy in addressing stigma, 1613 African American adolescents from four mid-sized cities participated in a randomized control trial. Participants received a sexual-risk reduction [Focus on Youth (FOY)] or general health curriculum [Promoting Health Among Teens (PHAT)]. Two cities received a culturally-tailored media intervention. Participants completed baseline, 3-, 6-, and 12-month surveys to measure HIV-related stigma and knowledge. Analysis of covariance tested for stigma and knowledge differences by media city status and curriculum/media city status (PHAT media vs. PHAT non-media, FOY media vs. FOY non-media; FOY media vs. PHAT media; FOY non-media vs. PHAT non-media) at each measurement. Hierarchical linear modeling (HLM) determined stigma and knowledge differences over time. Media participants demonstrated greater HIV-related knowledge (p<0.10) at 6 months and lower stigma at 3 months (p<0.10). FOY media participants had lower 3-month (p<0.05) and 12-month (p<0.10) stigma scores than non-media FOY participants. FOY media and non-media participants had greater knowledge than PHAT for all intervals after baseline. FOY media had lower stigma than PHAT media after baseline for all intervals after baseline. HLM indicated greater knowledge slopes for the media group (p<0.05). FOY media participants had greater knowledge slopes (p<0.05) relative to non-media FOY participants and media PHAT participants (p<0.01). A combination of a HIV risk-reduction curriculum and culturally-tailored media demonstrated some effectiveness in reducing stigma. Future use of media in HIV-prevention should include and evaluate effects on stigma. PMID:25738952

  20. The Effects of a Mass Media HIV-Risk Reduction Strategy on HIV-Related Stigma and Knowledge Among African American Adolescents

    PubMed Central

    Valois, Robert F.; DiClemente, Ralph J.; Carey, Michael P.; Stanton, Bonita; Romer, Daniel; Fletcher, Faith; Farber, Naomi; Brown, Larry K.; Vanable, Peter A.; Salazar, Laura F.; Juzang, Ivan; Fortune, Thierry

    2015-01-01

    Abstract HIV-related stigma undermines HIV prevention, testing, and treatment. Multipronged risk-reduction strategies may reduce stigma among African American adolescents. To test the effectiveness of a risk-reduction strategy in addressing stigma, 1613 African American adolescents from four mid-sized cities participated in a randomized control trial. Participants received a sexual-risk reduction [Focus on Youth (FOY)] or general health curriculum [Promoting Health Among Teens (PHAT)]. Two cities received a culturally-tailored media intervention. Participants completed baseline, 3-, 6-, and 12-month surveys to measure HIV-related stigma and knowledge. Analysis of covariance tested for stigma and knowledge differences by media city status and curriculum/media city status (PHAT media vs. PHAT non-media, FOY media vs. FOY non-media; FOY media vs. PHAT media; FOY non-media vs. PHAT non-media) at each measurement. Hierarchical linear modeling (HLM) determined stigma and knowledge differences over time. Media participants demonstrated greater HIV-related knowledge (p<0.10) at 6 months and lower stigma at 3 months (p<0.10). FOY media participants had lower 3-month (p<0.05) and 12-month (p<0.10) stigma scores than non-media FOY participants. FOY media and non-media participants had greater knowledge than PHAT for all intervals after baseline. FOY media had lower stigma than PHAT media after baseline for all intervals after baseline. HLM indicated greater knowledge slopes for the media group (p<0.05). FOY media participants had greater knowledge slopes (p<0.05) relative to non-media FOY participants and media PHAT participants (p<0.01). A combination of a HIV risk-reduction curriculum and culturally-tailored media demonstrated some effectiveness in reducing stigma. Future use of media in HIV-prevention should include and evaluate effects on stigma. PMID:25738952

  1. Social support buffering of the relation between low income and elevated blood pressure in at-risk African-American adults.

    PubMed

    Coulon, S M; Wilson, D K

    2015-10-01

    Socioeconomic disadvantage has been linked to elevated blood pressure (BP), and the purpose of this study was to assess whether interpersonal social supports buffer these adverse relations in African-American adults. In three communities matched demographically, a subsample of participants (N = 204) of the Positive Action for Today's Health trial provided measures of perceived social support, annual household income, and BP. Multiple regression analyses with cross-product interactions were conducted using follow-up data. The sample had a mean age of 52.8 years (SD = 15.1), and was predominantly female (66 %) with a high body mass index (M = 33.5, SD = 14.7). Results indicated an inverse relation between social support and diastolic BP (B = -.178, p = .005), and also an interaction with income (p = .046), such that higher social support related to lower diastolic BP in the lowest-income individuals (B = -1.05). The same direct (B = -.141, p = .025) and interacting (B = -1.42, p = .040) social support effects were present for systolic BP, however the omnibus model for systolic BP was not significant, F(6, 196) = 1.80, p = .09. The hypothesized buffering effect of social support on the adverse relation of income to BP was partially supported in at-risk African-American adults. Future prevention efforts for reducing the impact of socioeconomic stress on BP may aim to increase perceptions of social support. PMID:26156119

  2. How mantle slabs drive plate tectonics.

    PubMed

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina

    2002-10-01

    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction. PMID:12364804

  3. The African-American History of Martha's Vineyard.

    ERIC Educational Resources Information Center

    Weintraub, Elaine

    1993-01-01

    Reports on research into African American history and experiences in Martha's Vineyard (Massachusetts). Examines primary sources and oral traditions of African American cultural and social history from 1703 to the present. Discusses African American sailors, race relations, and contributions by African American individuals to the community. (CFR)

  4. “You’re losing your Ghanaianess”: understanding malaria decision-making among Africans visiting friends and relatives in the UK

    PubMed Central

    2014-01-01

    Background In the UK, the majority of imported malaria infections occur in the London area among UK residents of African origin who travel to Africa visiting friends and relatives (VFRs). Effective malaria prevention measures are available but there is little understanding of the factors that enhance and constrain their use among VFRs. Methods Semi-structured interviews were undertaken with Africans resident in London who visited friends and relatives in Nigeria and Ghana (n = 20) and with African VFRs recently treated for malaria (n = 6). Data collection took place between December 2007 and February 2011. Information on migration patterns and travel of respondents was collected and the data were analysed using a framework analysis approach. Results Knowledge of the link between mosquitoes and malaria was high. Factors influencing the use of mosquito avoidance methods included knowledge about the local environment, perceptions of the inevitability of contracting malaria, and a desire to fit with the norms of host families. Previous experience of bed nets, and the belief that more modern ways of preventing mosquito bites were available deterred people from using them. Chemoprophylaxis use was varied and influenced by: perceptions about continuing immunity to malaria; previous experiences of malaria illness; the cost of chemoprophylaxis; beliefs about the likely severity of malaria infections; the influence of friends in the UK; and, the way malaria is perceived and managed in Nigeria and Ghana. Malaria treatment was considered by many to be superior in Nigeria and Ghana than in the UK. A conceptual framework was developed to illustrate the manner in which these factors interact to affect malaria decisions. Conclusions The use of malaria prevention among VFRs needs to be understood not only in terms of individual risk factors but also in relation to the context in which decisions are made. For VFRs, malaria decisions are undertaken across two distinct social

  5. Phononic plate waves.

    PubMed

    Wu, Tsung-Tsong; Hsu, Jin-Chen; Sun, Jia-Hong

    2011-10-01

    In the past two decades, phononic crystals (PCs) which consist of periodically arranged media have attracted considerable interest because of the existence of complete frequency band gaps and maneuverable band structures. Recently, Lamb waves in thin plates with PC structures have started to receive increasing attention for their potential applications in filters, resonators, and waveguides. This paper presents a review of recent works related to phononic plate waves which have recently been published by the authors and coworkers. Theoretical and experimental studies of Lamb waves in 2-D PC plate structures are covered. On the theoretical side, analyses of Lamb waves in 2-D PC plates using the plane wave expansion (PWE) method, finite-difference time-domain (FDTD) method, and finite-element (FE) method are addressed. These methods were applied to study the complete band gaps of Lamb waves, characteristics of the propagating and localized wave modes, and behavior of anomalous refraction, called negative refraction, in the PC plates. The theoretical analyses demonstrated the effects of PC-based negative refraction, lens, waveguides, and resonant cavities. We also discuss the influences of geometrical parameters on the guiding and resonance efficiency and on the frequencies of waveguide and cavity modes. On the experimental side, the design and fabrication of a silicon-based Lamb wave resonator which utilizes PC plates as reflective gratings to form the resonant cavity are discussed. The measured results showed significant improvement of the insertion losses and quality factors of the resonators when the PCs were applied. PMID:21989878

  6. Genome-wide association study of a heart failure related metabolomic profile among African Americans in the Atherosclerosis Risk in Communities (ARIC) study.

    PubMed

    Yu, Bing; Zheng, Yan; Alexander, Danny; Manolio, Teri A; Alonso, Alvaro; Nettleton, Jennifer A; Boerwinkle, Eric

    2013-12-01

    Both the prevalence and incidence of heart failure (HF) are increasing, especially among African Americans, but no large-scale, genome-wide association study (GWAS) of HF-related metabolites has been reported. We sought to identify novel genetic variants that are associated with metabolites previously reported to relate to HF incidence. GWASs of three metabolites identified previously as risk factors for incident HF (pyroglutamine, dihydroxy docosatrienoic acid, and X-11787, being either hydroxy-leucine or hydroxy-isoleucine) were performed in 1,260 African Americans free of HF at the baseline examination of the Atherosclerosis Risk in Communities (ARIC) study. A significant association on chromosome 5q33 (rs10463316, MAF = 0.358, P-value = 1.92 × 10(-10) ) was identified for pyroglutamine. One region on chromosome 2p13 contained a nonsynonymous substitution in N-acetyltransferase 8 (NAT8) was associated with X-11787 (rs13538, MAF = 0.481, P-value = 1.71 × 10(-23) ). The smallest P-value for dihydroxy docosatrienoic acid was rs4006531 on chromosome 8q24 (MAF = 0.400, P-value = 6.98 × 10(-7) ). None of the above SNPs were individually associated with incident HF, but a genetic risk score (GRS) created by summing the most significant risk alleles from each metabolite detected 11% greater risk of HF per allele. In summary, we identified three loci associated with previously reported HF-related metabolites. Further use of metabolomics technology will facilitate replication of these findings in independent samples. PMID:23934736

  7. The Relation of Severity and Type of Community Violence Exposure to Emotional Distress and Problem Behaviors Among Urban African American Adolescents.

    PubMed

    Goldner, Jonathan; Gross, Israel M; Richards, Maryse H; Ragsdale, Brian L

    2015-01-01

    Severity level and type of exposure to community violence were examined to determine their effect on emotional distress and problem behaviors among 234 low-income urban African American early adolescents. There were 4 violence exposure scales developed from a principal component analysis of the Richters and Martinez (1993) exposure to violence scale: moderate and severe witnessing and moderate and severe victimization. Regression analyses indicated that moderate victimization was the most consistent predictor of emotional distress and behavioral problems, whereas moderate witnessing did not relate to any of the dependent variables. Severe victimization predicted depression and delinquency, whereas severe witnessing predicted posttraumatic stress disorder symptoms and delinquency. Witnessing and victimization scales based on severity of exposure better represented the experience than combining all data into a single exposure or simply witnessing and victimization scales. PMID:26118265

  8. A prospective study of the effects of marital status and family relations on young children's adjustment among African American and European American families.

    PubMed

    Shaw, D S; Winslow, E B; Flanagan, C

    1999-01-01

    The present study investigated the effects of divorce and family relations on young children's development prospectively, using an ethnically diverse sample of approximately 300 low-income families. We also were able to examine the moderating effects of ethnicity on child adjustment in always two-parent, to-be-divorced, already-divorced, and always single-parent families. Results indicated that to-be-divorced European American and African American families demonstrated higher rates of preschool-age behavior problems, and already-divorced families showed similar trends. Parental conflict and behavior problems accounted for predivorce differences in child behavior problems, whereas rejecting parenting accounted for differences in problem behavior between always single-parent and always two-parent families. The results are discussed in terms of the importance of ethnicity in influencing young, low-income children's adjustment to different family structures. PMID:10368919

  9. Generating Conflict for Greater Good: Utilizing Contingency Theory to Assess Black and Mainstream Newspapers as Public Relations Vehicles to Promote Better Health among African Americans

    PubMed Central

    Lumpkins, Crystal Y.; Bae, Jiyang; Cameron, Glen T.

    2010-01-01

    The potential use of strategic conflict management ( Wilcox and Cameron, 2006; Cameron, Wilcox, Reber and Shin ( in press) as a health advocacy tool in US African-American and mainstream newspapers, arguing that escalation of conflict can increase effectiveness of health-related news releases. For health communicators focusing on at-risk populations with poor health outcomes, such goals would include increased awareness of health problems and solutions, along with increased motivation arising from indignation over health disparities. Content analysis of 1,197 stories in 24 Black and 12 mainstream newspapers showed that more conflict factors were present in Black vs. mainstream newspapers, suggesting a way to strategically place health messages in news releases disseminated to newspapers that motivate at-risk publics to better health. The findings suggest that conflict factors such as racial disparity data regarding health issues may enhance media advocacy. PMID:22822291

  10. Generating Conflict for Greater Good: Utilizing Contingency Theory to Assess Black and Mainstream Newspapers as Public Relations Vehicles to Promote Better Health among African Americans.

    PubMed

    Lumpkins, Crystal Y; Bae, Jiyang; Cameron, Glen T

    2010-03-01

    The potential use of strategic conflict management ( Wilcox and Cameron, 2006; Cameron, Wilcox, Reber and Shin ( in press) as a health advocacy tool in US African-American and mainstream newspapers, arguing that escalation of conflict can increase effectiveness of health-related news releases. For health communicators focusing on at-risk populations with poor health outcomes, such goals would include increased awareness of health problems and solutions, along with increased motivation arising from indignation over health disparities. Content analysis of 1,197 stories in 24 Black and 12 mainstream newspapers showed that more conflict factors were present in Black vs. mainstream newspapers, suggesting a way to strategically place health messages in news releases disseminated to newspapers that motivate at-risk publics to better health. The findings suggest that conflict factors such as racial disparity data regarding health issues may enhance media advocacy. PMID:22822291

  11. Ion plating for the future

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1981-01-01

    The ion plating techniques are classified relative to the instrumental set up, evaporation media, and mode of transport. A distinction is drawn between the low vacuum (plasma) and high vacuum (ion beam) techniques. Ion plating technology is discussed at the fundamental and industrial level. At the fundamental level, the capabilities and limitations of the plasma (evaporant flux) and film characteristics are evaluated. And on the industrial level, the performance and potential uses of ion plated films are discussed.

  12. "My hair or my health:" Overcoming barriers to physical activity in African American women with a focus on hairstyle-related factors.

    PubMed

    Huebschmann, Amy G; Campbell, Lucille Johnson; Brown, Candace S; Dunn, Andrea L

    2016-01-01

    Physical activity disparities among African American (AA) women may be related to sociocultural barriers, including difficulties with restyling hair after exercise. We sought to identify physical activity barriers and facilitators in AA women with a focus on sociocultural factors related to hairstyle maintenance. Participants (n = 51) were AA women aged 19-73 years who completed valid surveys and participated in structured focus groups, stratified by age and physical activity levels, from November 2012 to February 2013. The Constant Comparison method was used to develop qualitative themes for barriers and facilitators. The most frequently reported general physical activity barrier among exercisers was "lack of money" (27%) and among non-exercisers was "lack of self-discipline" (57%). A hairstyle-related barrier of "sweating out my hairstyle" was reported by 7% of exercisers and 29% of non-exercisers. This hairstyle-related barrier included the need for extra time and money to restyle hair due to perspiration. Hairstyle-related facilitators included: prioritizing health over hairstyle and high self-efficacy to restyle hair after perspiration. Participants were interested in resources to simplify hairstyle maintenance. AA women whose hairstyle is affected by perspiration may avoid physical activity due to time and financial burdens. Increasing self-efficacy to restyle hair after perspiration may help to overcome this barrier. PMID:26495938

  13. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  14. Cranial reduction and fixation with a resorbable plate combined with cerebrospinal fluid shunting for difficult-to-manage macrocephaly related to hydrocephalus.

    PubMed

    Manwaring, Jotham C; Truong, Devon; Deukmedjian, Armen R; Carey, Carolyn M; Storrs, Bruce B; Rodriguez, Luis F; Tetreault, Lisa; Tuite, Gerald F

    2013-02-01

    The management of newborns with extreme macrocephaly related to hydrocephalus can be difficult; balancing the treatment of severe cranial deformity with optimal hydrocephalus management can be complicated. Excessive CSF drainage can result in significant suture overlap that leads to difficulties in patient positioning, secondary synostosis, and long-term aesthetic complications. Delayed cranial reduction and remodeling procedures carry significant risk, and the aesthetic outcomes have sometimes been poor. The authors describe a newborn with severe macrocephaly who underwent shunt placement followed by a limited cranial reduction and fixation procedure using an absorbable plate within the 1st week of life. The procedure produced an immediate intracranial volume reduction of 49%. This novel management strategy facilitated patient positioning, simplified hydrocephalus management, and provided an excellent aesthetic outcome. PMID:23231470

  15. Cenozoic intra-plate magmatism in the Darfur volcanic province: mantle source, phonolite-trachyte genesis and relation to other volcanic provinces in NE Africa

    NASA Astrophysics Data System (ADS)

    Lucassen, Friedrich; Pudlo, Dieter; Franz, Gerhard; Romer, Rolf L.; Dulski, Peter

    2013-01-01

    Chemical and Sr, Nd and Pb isotopic compositions of Late Cenozoic to Quaternary small-volume phonolite, trachyte and related mafic rocks from the Darfur volcanic province/NW-Sudan have been investigated. Isotope signatures indicate variable but minor crustal contributions. Some phonolitic and trachytic rocks show the same isotopic composition as their primitive mantle-derived parents, and no crustal contributions are visible in the trace element patterns of these samples. The magmatic evolution of the evolved rocks is dominated by crystal fractionation. The Si-undersaturated strongly alkaline phonolite and the Si-saturated mildly alkaline trachyte can be modelled by fractionation of basanite and basalt, respectively. The suite of basanite-basalt-phonolite-trachyte with characteristic isotope signatures from the Darfur volcanic province fits the compositional features of other Cenozoic intra-plate magmatism scattered in North and Central Africa (e.g., Tibesti, Maghreb, Cameroon line), which evolved on a lithosphere that was reworked or formed during the Neoproterozoic.

  16. Early initiation of sex, drug-related risk behaviors, and sensation-seeking among urban, low-income African-American adolescents.

    PubMed Central

    Stanton, B.; Li, X.; Cottrell, L.; Kaljee, L.

    2001-01-01

    The purpose of this study was to examine the relationship of early initiation of sex, drug-use, drug-trafficking, and sensation-seeking among urban, African-American adolescents. A longitudinal follow-up of 383 youth ages 9 to 15 years at baseline over four years with serial risk-assessments was used. Sexual experience and several drug-related risk behaviors increased significantly during the four-year study interval. Sensation-seeking scores were higher after the baseline assessment among youth reporting tobacco, alcohol, and marijuana use and were higher, both at baseline and through several follow-up assessments, among youth reporting drug-selling and sexual activity. At baseline, the correlations among drug-related risk behaviors were all strong, except those between initiation of sex and drug-related risk behaviors. However, over time, early initiators of sex were significantly more likely to report involvement in substance use and drug-delivery/sales than were late initiators. Youth reporting repeated involvement in drug-related activities were more likely to report intensive sexual involvement than they were to report experimental sex or no sex. Sensation-seeking scores were lower among youth reporting no involvement in risk behaviors. However, scores did not differ between youth exhibiting experimental behavior compared to youth demonstrating repeated risk involvement. These results support the need for alternative experiences for youth exhibiting high levels of sensation-seeking and the need for early drug/sexual risk prevention programs. PMID:12653400

  17. The Erosive Effects of Racism: Reduced Self-control Mediates the Relation between Perceived Racial Discrimination and Substance Use in African American Adolescents

    PubMed Central

    Gibbons, Frederick X.; O'Hara, Ross E.; Stock, Michelle L.; Gerrard, Meg; Weng, Chih-Yuan; Wills, Thomas A.

    2012-01-01

    Perceived racial discrimination, self-control, anger, and either substance use or use cognitions were assessed in two studies conducted with samples of African American adolescents. The primary goal was to examine the relation between discrimination and self-control over time; a second goal was to determine if that relation mediates the link between discrimination and substance use found in previous research. Study 1, which included a latent growth curve analysis with three waves of data, indicated that experience with discrimination (from age 10 to age 18) was associated with reduced self-control, which then predicted increased substance use. Additional analyses indicated anger was also a mediator of this discrimination to use relation. Study 2, which was experimental, showed that envisioning an experience involving discrimination was associated with an increase in substance-related responses to double entendre words (e.g., “pot,” “roach”) in a word association task, especially for participants who were low in dispositional self-control. The effect was again mediated by reports of anger. Thus, the “double mediation” pattern was: discrimination → more anger and reduced self-control → increased substance use and/or substance cognitions. Results are discussed in terms of the long-term impact of discrimination on self-control and health behavior. Implications for interventions aimed at ameliorating the negative effects of discrimination and low self-control on health are also discussed. PMID:22390225

  18. Localised Plate Motion on Venus

    NASA Astrophysics Data System (ADS)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.

  19. The relative contribution of viral and bacterial sexually transmitted infections on HIV acquisition in southern African women in the Methods for Improving Reproductive Health in Africa study.

    PubMed

    Venkatesh, K K; van der Straten, A; Cheng, H; Montgomery, E T; Lurie, M N; Chipato, T; Ramjee, G; Blanchard, K; Padian, N S; Mayer, K H; de Bruyn, G

    2011-04-01

    We assess the relative contribution of viral and bacterial sexually transmitted infections (STIs) on HIV acquisition among southern African women in a nested case-control study within the Methods for Improving Reproductive Health in Africa (MIRA) trial. Cases were women with incident HIV infection; controls were HIV-uninfected at the time of case seroconversion selected in a 1 to 3 case to control ratio (risk-set sampling), matched on study site and time of follow-up. Conditional logistic regression models were used to calculate adjusted odds ratios (AORs) and population-attributable fractions (PAF). Among 4948 enrolled women, we analysed 309 cases and 927 controls. The overall HIV incidence rate was 4.0 per 100 women-years. The incidence of HIV infection was markedly higher in women who had prevalent Herpes simplex virus type 2 (HSV-2) (AOR: 2.14; 95% confidence interval [CI]: 1.55-2.96), incident HSV-2 (AOR: 4.43; 95% CI: 1.77-11.05) and incident Neisseria gonorrhoeae (AOR: 6.92; 95% CI: 3.01-15.90). The adjusted PAF of HIV incidence for prevalent HSV-2 was 29.0% (95% CI: 16.8-39.3), for incident HSV-2 2.1% (95% CI: 0.6-3.6) and for incident N. gonorrhoeae 4.1% (95% CI: 2.5-5.8). Women's greatest risk factors for HIV acquisition were incident bacterial and viral STIs. Women-centred interventions aimed at decreasing HIV incidence in young African women need to address these common co-morbid conditions. PMID:21515755

  20. Tackle-related injury rates and nature of injuries in South African Youth Week tournament rugby union players (under-13 to under-18): an observational cohort study

    PubMed Central

    Burger, Nicholas; Lambert, Mike I; Viljoen, Wayne; Brown, James C; Readhead, Clint; Hendricks, Sharief

    2014-01-01

    Objectives The tackle situation is most often associated with the high injury rates in rugby union. Tackle injury epidemiology in rugby union has previously been focused on senior cohorts but less is known about younger cohorts. The aim of this study was to report on the nature and rates of tackle-related injuries in South African youth rugby union players representing their provinces at national tournaments. Design Observational cohort study. Setting Four South African Youth Week tournaments (under-13 Craven Week, under-16 Grant Khomo Week, under-18 Academy Week, under-18 Craven Week). Participants Injury data were collected from 3652 youth rugby union players (population at risk) in 2011 and 2012. Outcome measures Tackle-related injury severity (‘time-loss’ and ‘medical attention’), type and location, injury rate per 1000 h (including 95% CIs). Injury rate ratios (IRR) were calculated and modelled using a Poisson regression. A χ2 analysis was used to detect linear trends between injuries and increasing match quarters. Results The 2012 under-13 Craven Week had a significantly greater ‘time-loss’ injury rate when compared with the 2012 under-18 Academy Week (IRR=4.43; 95% CI 2.13 to 9.21, p<0.05) and under-18 Craven Week (IRR=3.52; 95% CI 1.54 to 8.00, p<0.05). The Poisson regression also revealed a higher probability of ‘overall’ (‘time-loss’ and ‘medical attention’ combined) and ‘time-loss’ tackle-related injuries occurring at the under-13 Craven Week. The proportion of ‘overall’ and ‘time-loss’ injuries increased significantly with each quarter of the match when all four tournaments were combined (p<0.05). Conclusions There was a difference in the tackle-related injury rate between the under-13 tournament and the two under-18 tournaments, and the tackle-related injury rate was higher in the final quarter of matches. Ongoing injury surveillance is required to better interpret these findings. Injury prevention strategies

  1. Dynamics and stress field of the Eurasian plate

    NASA Astrophysics Data System (ADS)

    Warners-Ruckstuhl, Karin; Govers, Rob; Wortel, Rinus

    2013-04-01

    extent, to lithospheric density structure and normal pressure from mantle flow. Stress observations require collision forces on the India-Eurasia boundary of 7.2 - 10.5 T N/m and on the Arabia-Eurasia boundary of 1.3 - 2.3 T N/m. Implication of mechanical equilibrium of the plate is that forces on the contacts with the African and Australian plates amount to 1.0 - 2.1 and 0 - 0.8 T N/m, respectively. The inferred collision forces are part of the best-fitting overall set of forces acting on the Eurasian plate, satisfying constraints from basic mechanics, absolute plate motion and stress field. We use our results to assess the validity of the classical view that the mean elevation of an orogenic plateau can be taken as a measure of the magnitude of the compressive (in this case: collision-related) forces involved. We find that for both the Tibetan and the Iranian plateau, two plateaus with significantly different average elevations, the horizontal force derived from the excess gravitational potential energy (collapse force) is in balance with the collision force, thus confirming the hypothesis of balanced topography.

  2. U.S. Professional Association Initiatives Related to Black South Africans: An Analysis and An Inventory. Information Exchange: Working Paper #2.

    ERIC Educational Resources Information Center

    Gottlieb, Julie D.

    The nature and level of activity among U.S. private sector groups seeking to expand educational opportunities for black South Africans is examined. The Information Exchange of the Institute of International Education (South African Programs) did research on such categories of organizations as foundations, church groups, educational institutions,…

  3. A Descriptive Qualitative Study Exploring Teacher and Parental Perceptions of African-American Middle School Male Students Related to Mathematics Performance

    ERIC Educational Resources Information Center

    Fowler, Crystal Nicole

    2013-01-01

    This qualitative descriptive case study explored the perceptions of parents and teachers of the academic achievement gap in mathematics between African-American middle school males and their White counterparts. Ten parents, both African-American and White, with students attending middle school in the Cherokee County School District and 5 teachers…

  4. Intervention Induced Changes on Parenting Practices, Youth Self-Pride and Sexual Norms to Reduce HIV-Related Behaviors among Rural African American Youths

    ERIC Educational Resources Information Center

    Murry, Velma McBride; Berkel, Cady; Chen, Yi-fu; Brody, Gene H.; Gibbons, Frederick X.; Gerrard, Meg

    2011-01-01

    AIDS is the leading killer of African Americans between the ages of 25 and 44, many of whom became infected when they were teenagers or young adults. The disparity in HIV infection rate among African Americans youth residing in rural Southern regions of the United States suggests that there is an urgent need to identify ways to promote early…

  5. Higher Education in Africa. Hearing before the Subcommittee on African Affairs of the Committee on Foreign Relations, United States Senate, One Hundred Third Congress, First Session (May 17, 1993).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Foreign Relations.

    Testimony on federal aid to higher education in Africa is recorded in this report of a congressional hearing. Subcommittee chairman Senator Paul Simon opened by describing his hope that more U.S. aid be directed to the relatively new but now deteriorating African institutions of higher education. John Hicks, from the Bureau for Africa at the…

  6. Emotion-Oriented Coping, Avoidance Coping, and Fear of Pain as Mediators of the Relationship between Positive Affect, Negative Affect, and Pain-Related Distress among African American and Caucasian College Women

    ERIC Educational Resources Information Center

    Lightsey, Owen Richard, Jr.; Wells, Anita G.; Wang, Mei-Chuan; Pietruszka, Todd; Ciftci, Ayse; Stancil, Brett

    2009-01-01

    The authors tested whether coping styles and fear of pain mediate the relationship between positive affect and negative affect on one hand and pain-related distress (PD) on the other. Among African American and Caucasian female college students, negative affect, fear of pain, and emotion-oriented coping together accounted for 34% of the variance…

  7. Nappes, tectonics of oblique plate convergence, and metamorphic evolution related to 140 million years of continuous subduction, Franciscan Complex, California

    SciTech Connect

    Wakabayashi, J. )

    1992-01-01

    This paper presents a new synthesis of Franciscan Complex tectonics, with the emphasis on the pre-San Andreas fault history of these rocks. Field relations suggest that the Franciscan is characterized by nappe structures that formed during sequential accretion at the trench. The presence of these structures along with other field relations, including the lack of evidence for large offset of conglomerate suites, indicates that strike-slip fault systems of large displacement ({gt}500 km) did not cut the Franciscan Complex during subduction. Regional geology and comparisons to modern arc-trench systems suggest that strike-slip faulting associated with oblique subduction took place inboard (east) of the Franciscan in the vicinity of the magmatic arc. The Franciscan varies along strike, because individual accreted elements (packets of trench sediment, seamounts, etc.) did not extend the full length of the trench. Different depths of underplating, distribution of post-metamorphic faulting, and level of erosion produced the present-day surface distribution of high P/T metamorphism. Franciscan Complex tectonic history is presented in this paper.

  8. Aluminum transfer method for plating plastics

    NASA Technical Reports Server (NTRS)

    Goodrich, W. D.; Stalmach, C. J., Jr.

    1977-01-01

    Electroless plating technique produces plate of uniform thickness. Hardness and abrasion resistance can be increased further by heat treatment. Method results in seamless coating over many materials, has low thermal conductivity, and is relatively inexpensive compared to conventional methods.

  9. Wild Termitomyces Species Collected from Ondo and Ekiti States Are More Related to African Species as Revealed by ITS Region of rDNA

    PubMed Central

    Oyetayo, Victor Olusegun

    2012-01-01

    Molecular identification of eighteen Termitomyces species collected from two states, Ondo and Ekiti in Nigeria was carried out using the internal transcribed spacer (ITS) region. The amplicons obtained from rDNA of Termitomyces species were compared with existing sequences in the NCBI GenBank. The results of the ITS sequence analysis discriminated between all the Termitomyces species (obtained from Ondo and Ekiti States) and Termitomyces sp. sequences obtained from NCBI GenBank. The degree of similarity of T1 to T18 to gene of Termitomyces sp. obtained from NCBI ranges between 82 and 99 percent. Termitomyces species from Garbon with ascension number AF321374 was the closest relative of T1 to T18 except T12 that has T. eurhizus and T. striatus as the closet relative. Phylogenetic tree generated with ITS sequences obtained from NCBI GenBank data revealed that T1 to T18 are more related to Termitomyces species indigenous to African countries such as Senegal, Congo, and Gabon. PMID:22649309

  10. Fracture severity of distal radius fractures treated with locking plating correlates with limitations in ulnar abduction and inferior health-related quality of life

    PubMed Central

    Tsitsilonis, Serafim; Machó, David; Manegold, Sebastian; Krapohl, Björn Dirk; Wichlas, Florian

    2016-01-01

    Introduction/background: The operative treatment of distal radius fractures has significantly increased after the introduction of locking plates. The aim of the present study was the evaluation of health-related quality of life, functional and radiological outcome of patients with distal radius fractures treated with the locking compression plate (LCP). Materials and methods: In the present study 128 patients (130 fractures) that were operatively treated with the LCP (2.4 mm/3.5 mm, Synthes®) were retrospectively evaluated. Mean follow-up was 22.7 months (SD 10.6). The fractures were radiographically evaluated (radial inclination, palmar tilt, ulnar variance) pre-, postoperatively and at the last follow-up visit. Range of motion (ROM) was documented. Grip strength was assessed with the use of a JAMAR dynamometer. The score for disabilities of the arm, shoulder and hand (DASH) and the Gartland-Werley score (GWS) were evaluated. Health-associated quality of life was assessed with use of SF-36 Health Survey. Results: Postoperative reduction was excellent; at the last follow-up visit only minimal reduction loss was observed. Except for pronation, a statistically significant decrease of ROM was present; in most cases that was not disturbing for the patients. The injured side achieved 83.9% of grip strength of the intact side. Mean DASH was 18.9 and mean GWS was 3.5. Health-associated quality of life was generally not compromised. However, limitations in ulnar abduction correlated with inferior quality of life. Fracture severity correlated with inferior quality of life, despite the absence of correlation with the functional and radiological outcome. Complication rate was low. Conclusions: Fracture severity seems to affect ulnar abduction and therefore patient quality of life, despite almost anatomical reduction; the objective and subjective scores were in most cases excellent. Modern everyday activities, such as keyboard typing, could be associated with the present

  11. Formation and metasomatism of continental lithospheric mantle in intra-plate and subduction-related tectonic settings

    NASA Astrophysics Data System (ADS)

    Ionov, Dmitri

    2010-05-01

    Our knowledge of the origin and evolution of the continental lithospheric mantle (CLM) remains fragmentary and partly controversial in spite of recent advances in petrologic, geochemical and geophysical studies of the deep Earth and experimental work. Debate continues on a number of essential topics, like relative contributions of partial melting, metasomatism and ‘re-fertilisation' as well as the timing, conditions and tectonic settings of those processes. These topics can be addressed by studies of ultramafic xenoliths in volcanic rocks which arguably provide the least altered samples of modern and ancient CLM. The subcontinental lithosphere is thought to be a mantle region from which melts have been extracted, thus making the lithosphere more refractory. Melting degrees can be estimated from Al contents while the depth of melt extraction can be assessed from Al-Fe (Mg#) relations in unmetasomatized melting residues in comparison with experimental data, e.g. [1]. High silica and opx in the residues may indicate melting in water-rich conditions. High-precision Mg# and Mn for olivine may constrain degrees and conditions of partial melting and/or metasomatism, tectonic settings, modal compositions (e.g. presence of garnet) and equilibration conditions of mantle peridotites [2]. These estimates require both adequate sampling and high-quality major element and modal data; sampling and analytical uncertainties in published work may contribute substantially to chemical heterogeneities (and different origins) inferred for CLM domains [3]. Very fertile peridotite xenolith suites are rare worldwide [3]. They were initially viewed as representing mantle domains that experienced only very small degrees of melt extraction but are attributed by some workers to ‘refertilization' of refractory mantle by percolating asthenospheric melts. Such alternative mechanisms might be valid for some rare hybrid and Fe-enriched peridotites but they fail to comprehensively explain modal

  12. Image and Reality in African Interethnic Relations: The Fulbe and Their Neighbors. Studies in Third World Societies, Publication Number Eleven.

    ERIC Educational Resources Information Center

    Schultz, Emily A., Ed.

    The eight articles in this collection focus on the Fulbe culture in West Africa, its intragroup relationships as well as its relations with other ethnic groups. Each article relates the concept of ethnicity to social and political differentiation among tribes. Following an introduction by Emily Schultz, John Lewis presents the findings of three…

  13. Child and Parent Perceptions of Relational Aggression within Urban Predominantly African American Children's Friendships: Examining Patterns of Concordance

    ERIC Educational Resources Information Center

    Waasdorp, Tracy Evian; Bradshaw, Catherine P.

    2009-01-01

    Increasing research documents the negative short- and long-term effects of relational aggression on children's behavior and social-emotional functioning. Although parents likely play an important role in the way children learn to cope with and attempt to resolve relational aggression, there is little research on this issue. The present study…

  14. Extending Findings of a Relation between Posttraumatic Stress Disorder and Emotion Dysregulation among African American Individuals: A Preliminary Examination of the Moderating Role of Gender

    PubMed Central

    Weiss, Nicole H; Tull, Matthew T; Dixon-Gordon, Katherine L; Gratz, Kim L

    2014-01-01

    Although previous literature highlights the robust relationship between posttraumatic stress disorder (PTSD) and emotion dysregulation across diverse racial/ethnic populations, few studies have examined factors that may influence levels of emotion dysregulation among African American individuals with PTSD. The goal of the current study was to extend previous findings by examining the moderating role of gender in the relationship between PTSD and emotion dysregulation in an African American sample. Participants were 107 African American undergraduates enrolled in a historically black college in the southern United States who reported exposure to a Criterion A traumatic event. Participants with probable PTSD (vs. no PTSD) reported significantly greater emotion dysregulation, both overall and across many of the specific dimensions. Although the main effect of gender on emotion dysregulation was not statistically significant, results revealed a significant interaction between gender and probable PTSD status for overall emotion dysregulation and the specific dimensions of difficulties controlling impulsive behaviors when distressed, limited access to emotion regulation strategies perceived as effective, and lack of emotional clarity. Specifically, post-hoc analyses revealed a significant association between probable PTSD and heightened emotion dysregulation among African American women but not African American men, with African American women with probable PTSD reporting significantly higher levels of these dimensions of emotion dysregulation than all other groups. Findings highlight the relevance of emotion dysregulation to PTSD among African American women in particular, suggesting the importance of assessing and treating emotion dysregulation within this population. PMID:25392846

  15. A new velocity field for Africa from combined GPS and DORIS space geodetic Solutions: Contribution to the definition of the African reference frame (AFREF)

    NASA Astrophysics Data System (ADS)

    Saria, E.; Calais, E.; Altamimi, Z.; Willis, P.; Farah, H.

    2013-04-01

    We analyzed 16 years of GPS and 17 years of Doppler orbitography and radiopositioning integrated by satellite (DORIS) data at continuously operating geodetic sites in Africa and surroundings to describe the present-day kinematics of the Nubian and Somalian plates and constrain relative motions across the East African Rift. The resulting velocity field describes horizontal and vertical motion at 133 GPS sites and 9 DORIS sites. Horizontal velocities at sites located on stable Nubia fit a single plate model with a weighted root mean square residual of 0.6 mm/yr (maximum residual 1 mm/yr), an upper bound for plate-wide motions and for regional-scale deformation in the seismically active southern Africa and Cameroon volcanic line. We confirm significant southward motion ( ˜ 1.5 mm/yr) in Morocco with respect to Nubia, consistent with earlier findings. We propose an updated angular velocity for the divergence between Nubia and Somalia, which provides the kinematic boundary conditions to rifting in East Africa. We update a plate motion model for the East African Rift and revise the counterclockwise rotation of the Victoria plate and clockwise rotation of the Rovuma plate with respect to Nubia. Vertical velocities range from - 2 to +2 mm/yr, close to their uncertainties, with no clear geographic pattern. This study provides the first continent-wide position/velocity solution for Africa, expressed in International Terrestrial Reference Frame (ITRF2008), a contribution to the upcoming African Reference Frame (AFREF). Except for a few regions, the African continent remains largely under-sampled by continuous space geodetic data. Efforts are needed to augment the geodetic infrastructure and openly share existing data sets so that the objectives of AFREF can be fully reached.

  16. Obesity and African Americans

    MedlinePlus

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  17. Plate Tectonics: From Plate Boundary Zone Tectonics To Extensive Intraplate Tectonics

    NASA Astrophysics Data System (ADS)

    Ishikawa, M.

    2004-12-01

    mantle is about 15x1012N/m. The weakening of wet mantle, therefore, result in the dramatic reduction of cumulative strength of lithosphere from 17x1012N/m (dry) to 3x1012N/m (wet). Forces of ridge push appear to be in the range of 3.9x1012N/m. Ridge push is probably the principal driving force for intraplate deformation after amalgamation of continent. Dry upper mantle carries much of the ridge push force. The magnitude of cumulative lithospheric strength is much higher than that of wet lithosphere and far exceeds the ridge push forces. In contrast, the cumulative strength of wet lithosphere is comparable to the ridge push force, suggesting ridge push forces are enough to cause intraplate deformation of wet continental plate. I infer that slab dehydration along numerous subduction zones during collision of microcontinent and island arcs at late Paleozoic/Mesozoic caused extensive wetting of uppermost mantle beneath Asia, resulting in extensive weakening of plate. Since Proterozoic/Phanerozoic boundary, collision events such as East African orogeny, Variscan orogeny, Alpine orogeny and Himalayan orogeny have involved relatively extensive intraplatel tectonics in Gondwana supercontinent, Pangea supercontinent, Europe continent and Asia continent respectively whereas Archean/Proterozoic continental collisions give rise to plate boundary zone tectonics. It probably reflects initiation of return flow of H2O component into mantle at about 750 million years ago (Maruyama, 1999). I conclude that fragile continental plate have been established during late Proterozoic to Phanerozoic assembly of continent, and extensive intraplate tectonics started to operate on earth at Proterozoic/Phanerozoic boundary.

  18. The East African rift system

    NASA Astrophysics Data System (ADS)

    Chorowicz, Jean

    2005-10-01

    This overview paper considers the East African rift system (EARS) as an intra-continental ridge system, comprising an axial rift. It describes the structural organization in three branches, the overall morphology, lithospheric cross-sections, the morphotectonics, the main tectonic features—with emphasis on the tension fractures—and volcanism in its relationships with the tectonics. The most characteristic features in the EARS are narrow elongate zones of thinned continental lithosphere related to asthenospheric intrusions in the upper mantle. This hidden part of the rift structure is expressed on the surface by thermal uplift of the rift shoulders. The graben valleys and basins are organized over a major failure in the lithospheric mantle, and in the crust comprise a major border fault, linked in depth to a low angle detachment fault, inducing asymmetric roll-over pattern, eventually accompanied by smaller normal faulting and tilted blocks. Considering the kinematics, divergent movements caused the continent to split along lines of preexisting lithospheric weaknesses marked by ancient tectonic patterns that focus the extensional strain. The hypothesis favored here is SE-ward relative divergent drifting of a not yet well individualized Somalian plate, a model in agreement with the existence of NW-striking transform and transfer zones. The East African rift system comprises a unique succession of graben basins linked and segmented by intracontinental transform, transfer and accommodation zones. In an attempt to make a point on the rift system evolution through time and space, it is clear that the role of plume impacts is determinant. The main phenomenon is formation of domes related to plume effect, weakening the lithosphere and, long after, failure inducing focused upper mantle thinning, asthenospheric intrusion and related thermal uplift of shoulders. The plume that had formed first at around 30 Ma was not in the Afar but likely in Lake Tana region (Ethiopia

  19. Polymorphism of the human factor H-related gene (FHR-1) and of factor H in a West African individual

    SciTech Connect

    Meyer, C.G.; Skerka, C.; Zipfel, P.F.

    1995-03-01

    The human factor H-related 1 (FHR-1) protein is structurally and immunogenically related to the regulatory complement protein factor H (FH). Polymorphism of the FHR-1 gene is indicated by the nucleotide differences as described by the five cDNA clones isolated so far. In order to further analyze this polymorphism we identified PCR-primers which allow the simultaneous amplification of FHR-1 and FH alleles in a single polymerase chain reaction (PCR). By DNA sequence analysis, two novel FHR-1 variants and one as yet unrecognized FH allele could be characterized in an individual from Benin, West Africa. 2 refs., 1 fig.

  20. Depressive symptoms are more strongly related to executive functioning and episodic memory among African American compared with non-Hispanic White older adults.

    PubMed

    Zahodne, Laura B; Nowinski, Cindy J; Gershon, Richard C; Manly, Jennifer J

    2014-11-01

    We examined whether the reserve capacity model can be extended to cognitive outcomes among older African Americans. Two hundred and ninety-two non-Hispanic Whites and 37 African Americans over age 54 participated in the normative study for the NIH Toolbox for the Assessment of Neurological and Behavioral Function. Multiple-group path analysis showed that associations between depressive symptoms and cognition differed by race, independent of age, education, reading level, income, health, and recruitment site. Depressive symptoms were associated with slowed processing speed among Whites and worse task-switching, inhibition, and episodic memory among African Americans. African Americans may be more vulnerable to negative effects of depression on cognition than non-Hispanic Whites. Further research is needed to explicate the psychological and neurobiological underpinnings of this greater vulnerability. PMID:25280795

  1. Selfing ability and dispersal are positively related, but not affected by range position: a multispecies study on southern African Asteraceae.

    PubMed

    de Waal, C; Rodger, J G; Anderson, B; Ellis, A G

    2014-05-01

    Dispersal and breeding system traits are thought to affect colonization success. As species have attained their present distribution ranges through colonization, these traits may vary geographically. Although several theories predict associations between dispersal ability, selfing ability and the relative position of a population within its geographic range, there is little theoretical or empirical consensus on exactly how these three variables are related. We investigated relationships between dispersal ability, selfing ability and range position across 28 populations of 13 annual, wind-dispersed Asteraceae species from the Namaqualand region of South Africa. Controlling for phylogeny, relative dispersal ability--assessed from vertical fall time of fruits--was positively related to an index of autofertility--determined from hand-pollination experiments. These findings support the existence of two discrete syndromes: high selfing ability associated with good dispersal and obligate outcrossing associated with lower dispersal ability. This is consistent with the hypothesis that selection for colonization success drives the evolution of an association between these traits. However, no general effect of range position on dispersal or breeding system traits was evident. This suggests selection on both breeding system and dispersal traits acts consistently across distribution ranges. PMID:24735437

  2. How Are the Mathematical Identities of Low Achieving South African Eleventh Graders Related to Their Ability to Solve Mathematical Tasks?

    ERIC Educational Resources Information Center

    Cranfield, Corvell

    2013-01-01

    The construct of mathematical identity has recently been widely used in mathematics education with the intention to understand how students relate to and engage (or disengage) with mathematics. Grootenboer and Zevenbergen (2008) define mathematical identity as the students' knowledge, abilities, skills, beliefs, dispositions, attitudes and…

  3. Violence Exposure and Health-Related Risk among African American Adolescent Female Detainees: A Strategy for Reducing Recidivism

    ERIC Educational Resources Information Center

    Woodson, Kamilah M.; Hives, Courtney C.; Sanders-Phillips, Kathy

    2010-01-01

    Juvenile crime and violent victimization continue to be significant social problems, in that adolescents, females in particular, are likely to participate in health-related risk behaviors as a result of having been victimized or exposed to a violent environment. Specifically, abuse, neglect, sexual molestation, poverty, and witnessing violence are…

  4. Cultural similarities and differences between a sample of Black/African and colored women in South Africa: convergence of risk related to substance use, sexual behavior, and violence.

    PubMed

    Sawyer, Kyla Marie; Wechsberg, Wendee M; Myers, Bronwyn J

    2006-01-01

    South Africa is one of the six southern African countries where the HIV levels for childbearing women are 20% or higher. We conducted two focus groups aimed at developing an understanding of the intersections of substance abuse, sexual behavior, and violence affecting the lives of women of color in Cape Town, South Africa. Both Colored and Black/African participants reported using cannabis, methaqualone, and alcohol, although they differed on other drugs used. Black/African women also used heroin, and crack cocaine, whereas Colored women used methamphetamines. For participants in both groups, relationships with men affected sexual and substance use risk behaviors. Although the Black/African women did not trust men to use condoms, the Colored women in the study believed that almost all men use condoms. Both groups of women reported high rates of violence, with Colored participants reporting more gang violence and woman-on-woman violence compared with Black/African participants. The paper discusses these issues, as well as the implications for adapting a culturally specific, brief woman-focused HIV prevention intervention for the South African context. PMID:17000612

  5. Recent plate motions and crustal deformation

    SciTech Connect

    Lisowski, M. )

    1991-01-01

    Reports by U.S. workers on geodetic measurements of recent plate motions or crustal deformation published in 1987-1990 are reviewed. The review begins with global plate motions, proceeds through plate boundaries in California, Alaska, and the Pacific Northwest, and finishes with volcanic phenomena, monument stability and longevity, and GPS relative position measurements. 184 refs.

  6. Forming Weld Lands On Metal Plates

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Forming shoe pounds edge of newly inserted plate workpiece. After many passes of shoe and advances of plate, thick land builds up at edge. Workpiece heated to enable metal to flow without strain hardening. Proposed upset-forming process replaces relatively expensive, time-consuming, and wasteful process in which integral weld lands created by machining metal away from plates everywhere except at lands.

  7. 49 CFR 451.23 - Plate specifications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Plate specifications. 451.23 Section 451.23 Transportation Other Regulations Relating to Transportation (Continued) COAST GUARD, DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS TESTING AND APPROVAL OF CONTAINERS Safety Approval Plate § 451.23 Plate specifications. (a) The...

  8. A deletion variant of the alpha2b-adrenoceptor is related to emotional memory in Europeans and Africans.

    PubMed

    de Quervain, Dominique J-F; Kolassa, Iris-Tatjana; Ertl, Verena; Onyut, P Lamaro; Neuner, Frank; Elbert, Thomas; Papassotiropoulos, Andreas

    2007-09-01

    Emotionally arousing events are recalled better than neutral events. This phenomenon, which helps us to remember important and potentially vital information, depends on the activation of noradrenergic transmission in the brain. Here we show that a deletion variant of ADRA2B, the gene encoding the alpha2b-adrenergic receptor, is related to enhanced emotional memory in healthy Swiss subjects and in survivors of the Rwandan civil war who experienced highly aversive emotional situations. PMID:17660814

  9. Impact of Antiretroviral Therapy on Health-Related Quality of Life among South African Women in the CAPRISA 002 Acute Infection Study

    PubMed Central

    Tomita, Andrew; Garrett, Nigel; Werner, Lise; Burns, Jonathan K.; Ngcobo, Nelisiwe; Zuma, Nomthandazo; Mlisana, Koleka; van Loggerenberg, Francois; Abdool Karim, Salim S.

    2014-01-01

    Concerns are often raised regarding potentially adverse effects of antiretroviral therapy (ART) on health-related quality of life (HRQoL), but there is limited longitudinal data to prove this. Building on our prior investigation, we examined the impact of ART on HRQoL among HIV-infected South African women with extensive follow-up in the CAPRISA 002 Acute Infection Cohort Study. Overall HRQoL and five sub-domains [physical well-being (PWB), emotional well-being (EWB), functional and global well-being (FGWB), social well-being (SWB) and cognitive functioning (CF)] were assessed using the Functional Assessment of HIV Infection (FAHI) instrument. Our analyses comparing FAHI scores between pre-ART (established infection) and ART phases using paired Wilcoxon signed-rank tests and adjusted mixed-effects regression models revealed improvements on ART in overall HRQoL, and in PWB, EWB, and SWB, but not in FGWB and CF. No long-term adverse impact of ART on HRQoL was detected, providing additional non-biomedical support to early treatment strategies. PMID:24849623

  10. Present-day plate motions

    NASA Technical Reports Server (NTRS)

    Minster, J. B.; Jordan, T. H.

    1977-01-01

    A data set comprising 110 spreading rates, 78 transform fault azimuths and 142 earthquake slip vectors was inverted to yield a new instantaneous plate motion model, designated RM2. The mean averaging interval for the relative motion data was reduced to less than 3 My. A detailed comparison of RM2 with angular velocity vectors which best fit the data along individual plate boundaries indicates that RM2 performs close to optimally in most regions, with several notable exceptions. On the other hand, a previous estimate (RM1) failed to satisfy an extensive set of new data collected in the South Atlantic Ocean. It is shown that RM1 incorrectly predicts the plate kinematics in the South Atlantic because the presently available data are inconsistent with the plate geometry assumed in deriving RM1. It is demonstrated that this inconsistency can be remedied by postulating the existence of internal deformation with the Indian plate, although alternate explanations are possible.

  11. Understanding traditional African healing

    PubMed Central

    MOKGOBI, M.G.

    2015-01-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists. PMID:26594664

  12. Elastic plate spallation

    NASA Technical Reports Server (NTRS)

    Oline, L.; Medaglia, J.

    1972-01-01

    The dynamic finite element method was used to investigate elastic stress waves in a plate. Strain displacement and stress strain relations are discussed along with the stiffness and mass matrix. The results of studying point load, and distributed load over small, intermediate, and large radii are reported. The derivation of finite element matrices, and the derivation of lumped and consistent matrices for one dimensional problems with Laplace transfer solutions are included. The computer program JMMSPALL is also included.

  13. The relational dynamics of hegemonic masculinity among South African men and women in the context of HIV.

    PubMed

    Stern, Erin; Buikema, Rosemarie

    2013-01-01

    In South Africa, the frequent positioning of men's sexual behaviours as a prime driver of the HIV epidemic has generated much interest in men's sexuality. However, the relational nature of dominant male norms that exacerbate the risk of HIV transmission is inadequately understood. This study used sexual biographies to explore how men and women negotiate gendered norms and how this affects their sexual and reproductive health (SRH). A total of 50 sexual-history interviews and 10 focus group discussions were conducted with men, and 25 sexual-history interviews with women, with participants sampled from three age categories (ages 18-24, 25-55 and 55+years), a range of cultural and racial backgrounds and urban and rural sites across five provinces in South Africa. The narratives illustrate that men and women's SRH is largely dependent on the type and quality of their relationships. Men's sexuality was regularly depicted as being detached from intimacy and uncontrollable, which was premised as being opposite from and/or superior to women's sexuality and could justify men's high-risk sexual behaviours. Yet many participants also supported gender equitable relationships and endorsed accountable and healthy SRH behaviours. The narratives reveal that HIV-risky dominant male norms should be addressed relationally for the sake of better SRH outcomes. PMID:23805918

  14. Evaluation of the Interplate and Intraplate Deformations of the African Continent Using cGNSS Data

    NASA Astrophysics Data System (ADS)

    Apolinário, J. P.; Fernandes, R. M. S.; Bos, M. S.; Meghraoui, M.; Miranda, J. M. A.

    2014-12-01

    Two main plates, Nubia and Somalia, plus some few more tectonic blocks in the East African Rift System (EARS) delimit the African continent. The major part of the external plate boundaries of Africa is well defined by oceanic ridge systems with the exception of the Nubia-Eurasia complex convergence-collision tectonic zone. In addition, the number and distribution of the tectonic blocks along the EARS region is a major scientific issue that has not been completely answered so far. Nevertheless, the increased number of cGNSS (continuous Global Navigation Satellite Systems) stations in Africa with sufficient long data span is helping to better understand and constrain the complex sub-plate distribution in the EARS as well as in the other plate boundaries of Africa. This work is the geodetic contribution for the IGCP-Project 601 - "Seismotectonics and Seismic Hazards in Africa". It presents the current tectonic relative motions of the African continent based on the analysis of the estimated velocity field derived from the existing network of cGNSS stations in Africa and bordering plate tectonics. For the majority of the plate pairs, we present the most recent estimation of their relative velocity using a dedicated processing. The velocity solutions are computed using HECTOR, a software that takes into account the existing temporal correlations between the daily solutions of the stations. It allows to properly estimate the velocity uncertainties and to detect any artifacts in the time-series. For some of the plate pairs, we compare our solutions of the angular velocities with other geodetic and geophysical models. In addition, we also study the sensitivity of the derived angular velocity to changes in the data (longer data-span for some stations) for tectonic units with few stations, and in particular for the Victoria and Rovuma blocks of the EARS. Finally, we compute estimates of velocity fields for several sub-regions correlated with the seismotectonic provinces and

  15. Plume and plate controlled hotspot trails in the South Atlantic

    NASA Astrophysics Data System (ADS)

    O'Connor, John; Jokat, Wilfried; le Roex, Anton; Class, Cornelia; Wijbrans, Jan; Keßling, Stefanie; Kuiper, Klaudia; Nebel, Oliver

    2013-04-01

    Discovering if hotspots observed on the Earth's surface are explained by underlying plumes rising from the deep mantle or by shallow plate-driven processes continues to be an essential goal in Earth Science. Key evidence underpinning the mantle plume concept is the existence of age-progressive volcanic trails recording past plate motion relative to surface hotspots and their causal plumes. Using the icebreaker RV Polarstern, we sampled scattered hotspot trails on the 2,000 km-wide southeast Atlantic hotspot swell, which projects down to one of the Earth's two largest and deepest regions of slower-than-average seismic wave speed - the Africa Low Shear Wave Velocity Province - caused by a massive thermo-chemical 'pile' on the core-mantle boundary. We showed recently using Ar/Ar isotopic ages - and crustal structure and seafloor ages - that these hotspot trails are age progressive and formed synchronously across the swell, consistent with African plate motion over plumes rising from the stable edge of a Low Shear Wave Velocity Province (LLSVP) (O'Connor et al., 2012). We showed furthermore that hotspot trails formed initially only at spreading boundaries at the outer edges of the swell until roughly 44 million years ago, when they started forming across the swell, far from spreading boundaries in lithosphere that was sufficiently weak (young) for plume melts to reach the surface. We concluded that if plume melts formed synchronous age progressive hotspot trails whenever they could penetrate the lithosphere, then hotspot trails in the South Atlantic are controlled by the interplay between deep plumes and the shallow motion and structure of the African plate. If the distribution of hotspot trails reflects where plume melts could or could not penetrate the continental or oceanic lithosphere then plumes could have been active for significantly longer than indicated by their volcanic chains. This provides a mechanism for extended late stage interplay between deep mantle

  16. Central North Atlantic Plate Motions over the Last 40 Million Years.

    PubMed

    Phillips, J D; Luyendyk, B P

    1970-11-13

    The relative motion vector for the North American and African plates has been determined from detailed charting of the trend of the Atlantis fracture zone for over 1000 kilometers in the central North Atlantic near 30 degrees N and from identification of marine magnetic anomalies and deep-sea drilling results. The vector (pole) is located at 52.5 degrees N, 34 degrees W and has a magnitude (opening rate) of 5.7 x 10(-7) degree per year. Major changes in either the pole location or the opening rate are not evident for the last 40 million years. PMID:17776338

  17. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  18. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  19. Mind-Body Interventions to Reduce Risk for Health Disparities Related to Stress and Strength Among African American Women: The Potential of Mindfulness-Based Stress Reduction, Loving-Kindness, and the NTU Therapeutic Framework

    PubMed Central

    Woods-Giscombé, Cheryl L.; Black, Angela R.

    2011-01-01

    In the current article, the authors examine the potential role of mind-body interventions for preventing or reducing health disparities in a specific group—African American women. The authors first discuss how health disparities affect this group, including empirical evidence regarding the influence of biopsychosocial processes (e.g., psychological stress and social context) on disparate health outcomes. They also detail how African American women's unique stress experiences as a result of distinct sociohistorical and cultural experiences related to race and gender potentially widen exposure to stressors and influence stress responses and coping behaviors. Using two independent, but related, frameworks (Superwoman Schema [SWS] and the Strong Black Woman Script [SBW-S]), they discuss how, for African American women, stress is affected by “strength” (vis-à-vis resilience, fortitude, and self-sufficiency) and the emergent health-compromising behaviors related to strength (e.g., emotional suppression, extraordinary caregiving, and self-care postponement). The authors then describe the potential utility of three mind-body interventions—mindfulness-based stress reduction (MBSR), loving-kindness meditation (LKM), and NTU psychotherapy—for specifically targeting the stress-, strength-, and contextually related factors that are thought to influence disparate outcomes for African American women. Self-awareness, self-care, inter- and intrapersonal restorative healing and a redefinition of inner strength may manifest through developing a mindfulness practice to decrease stress-related responses; using LKM to cultivate compassion and forgiveness for self and others; and the balance of independence and interdependence as a grounding NTU principle for redefining strength. The authors conclude with a discussion of potential benefits for integrating key aspects of the interventions with recommendations for future research. PMID:21479157

  20. Miocene to Pliocene changes in South African hydrology and vegetation in relation to the expansion of C4 plants

    NASA Astrophysics Data System (ADS)

    Dupont, Lydie M.; Rommerskirchen, Florian; Mollenhauer, Gesine; Schefuß, Enno

    2013-08-01

    The Miocene expansion of C4 plants (mainly tropical grasses) between 8 and 4 million years (Ma) remains an enigma since regional differences in the timing of the expansion rules out decreased CO2 (pCO2) as a dominant forcing [e.g. Tipple and Pagani, 2007. The early origins of terrestrial C4 photosynthesis. Annu. Rev. Earth Planet. Sci. 35, 435-461]. Other environmental factors, such as low-latitude aridity and seasonality have been proposed to explain the low tree versus grass ratio found in savannahs and tropical grasslands of the world, but conclusive evidence is missing. Here we use pollen and stable carbon (δ13C) and hydrogen (δD) isotope ratios of terrestrial plant wax from a South Atlantic sediment core (ODP Site 1085) to reconstruct Miocene to Pliocene changes of vegetation and rainfall regime of western southern Africa. Our results reveal changes in the relative amount of precipitation and indicate a shift of the main moisture source from the Atlantic to the Indian Ocean during the onset of a major aridification 8 Ma ago. We emphasize the importance of declining precipitation during the expansion of C4 and CAM (mainly succulent) vegetation in South Africa. We suggest that the C4 plant expansion resulted from an increased equator-pole temperature gradient caused by the initiation of strong Atlantic Meridional Overturning Circulation following the shoaling of the Central American Seaway during the Late Miocene.

  1. Wildlife-associated zoonotic diseases in some southern African countries in relation to game meat safety: a review.

    PubMed

    Bekker, Johan L; Hoffman, Louw C; Jooste, Piet J

    2012-01-01

    With on-going changes in land use practices from conventional livestock farming to commercial, wildlife-based activities, the interface or interaction between livestock and wildlife is increasing. As part of the wildlife-based activities of ecotourism, breeding and hunting, game farmers are also exploring the utilisation of meat from hunted or harvested game. The expanding interface or increased interaction between livestock and wildlife increases the risk of disease incidence and the emergence of new diseases or the re-emergence of previously diagnosed diseases. The risk is not only related to domestic and wild animal health, but also to the occupational hazards that it poses to animal handlers and the consumers of game meat. This review endeavours to highlight the role that game plays in the spreading of zoonotic diseases to other animals and humans. Examples of zoonotic diseases that have occurred in wild animals in the past, their relevance and risk have been summarised and should function as a quick reference guide for wildlife veterinarians, ecologists, farmers, hunters, slaughter staff, processors and public health professionals. PMID:23327327

  2. Proxy Assessment of Health-Related Quality of Life in African American and White Respondents With Prostate Cancer

    PubMed Central

    Pickard, A. Simon; Lin, Hsiang-Wen; Knight, Sara J.; Sharifi, Roohollah; Wu, Zhigang; Hung, Shih-Ying; Witt, Whitney P.; Chang, Chih-Hung; Bennett, Charles L.

    2011-01-01

    Objectives An emerging issue in the proxy literature is whether specifying different proxy viewpoints contributes to different health-related quality of life (HRQL) assessments, and if so, how might each perspective be informative in medical decision making. The aims of this study were to determine if informal caregiver assessments of patients with prostate cancer differed when prompted from both the patient perspective (proxy-patient) and their own viewpoint (proxy-proxy), and to identify factors associated with differences in proxy perspectives (ie, the intraproxy gap). Research Design and Methods Using a cross-sectional design, prostate cancer patients and their informal caregivers were recruited from urology clinics in the Jesse Brown Veterans Affairs Healthcare System in Chicago. Dyads assessed HRQL using the EQ-5D visual analog scale (VAS) and EORTC QLQ-C30. Results Of 87 dyads, most caregivers were female (83%) and were spouses/partners (58%). Mean difference scores between proxy-patient and proxy-proxy perspectives were statistically significant for QLQ-C30 physical and emotional functioning, and VAS (all P < 0.05), with the proxy-patient perspective closer to patient self-report. Emotional functioning had the largest difference, mean 6.0 (SD 12.8), an effect size = 0.47. Factors weakly correlated with the intraproxy gap included relationship (spouse) and proxy gender for role functioning, and health literacy (limited/functional) for physical functioning (all P < 0.05, 0.20 < r < 0.35). Conclusions Meaningful differences between proxy-patient and proxy-proxy perspectives on mental health were consistent with a conceptual framework for understanding proxy perspectives. Prompting different proxy viewpoints on patient health could help clinicians identify patients who may benefit from clinical intervention. PMID:19169118

  3. From lizard body form to serpentiform morphology: The atlas-axis complex in African cordyliformes and their relatives.

    PubMed

    Čerňanský, Andrej

    2016-04-01

    The comparative vertebral morphology of the atlas-axis complex in cordyliforms, xantusiid and several skinks is studied here. These lizards are particularly interesting because of their different ecological adaptations and anti-predation strategies, where conformation ranges from the lizard-like body to a snake-like body. This transition to serpentiform morphology shows several evolutionary patterns in the atlas-axis complex: 1) the zygapophyseal articulations are lost in the early stage of the transition. In contrast to mammals, the atlas is more or less locked to the axis in lepidosaurs, but the absence of zygapophyseal articulation releases this locking for rotation. However despite its serpentiform morphology, Chamaesaura is different, in possessing this articulation; 2) the first intercentrum of Chamaesaura and Tetradactylus africanus (serpentiform grass-swimmers) is fully curved anteriorly, underlying the occipital condyle. While this limits ventral skull rotation beyond a certain angle, it locks the skull, which is a crucial adaptation for a sit-and-wait position in grassland habitats that needs to keep the head stabilized; and 3) in Acontias, most of the atlas articular surface with the occipital condyle is formed by the lateral aspect of the articulation area relative to the area located in the dorsal region of the slightly reduced intercentrum. A similar state occurs in amphisbaenians, most likely reflecting a fossorial lifestyle of the limbless lizards. Although Chamaesaura and Tetradactylus live sympatrically in grasslands, Chamaesaura differs in several ways in atlas-axis complex: for example, aforementioned presence of the atlas-axis zygapophyseal articulation, and long posterodorsal processes. Its occipital condyle protrudes further posteriorly, placing the atlas-axis complex further from the endocranium than in Tetradactylus. Hence, adaptation in the same niche, even among sister clades, can lead to different atlas-axis morphology due to different

  4. African horse sickness.

    PubMed

    Zientara, S; Weyer, C T; Lecollinet, S

    2015-08-01

    African horse sickness (AHS) is a devastating disease of equids caused by an arthropod-borne virus belonging to the Reoviridae family, genus Orbivirus. It is considered a major health threat for horses in endemic areas in sub-Saharan Africa. African horse sickness virus (AHSV) repeatedly caused large epizootics in the Mediterranean region (North Africa and southern Europe in particular) as a result of trade in infected equids. The unexpected emergence of a closely related virus, the bluetongue virus, in northern Europe in 2006 has raised fears about AHSV introduction into Europe, and more specifically into AHSV-free regions that have reported the presence of AHSV vectors, e.g. Culicoides midges. North African and European countries should be prepared to face AHSV incursions in the future, especially since two AHSV serotypes (serotypes 2 and 7) have recently spread northwards to western (e.g. Senegal, Nigeria, Gambia) and eastern Africa (Ethiopia), where historically only serotype 9 had been isolated. The authors review key elements of AHS epidemiology, surveillance and prophylaxis. PMID:26601437

  5. Forced relative displacements of the core and mantle as the basic mechanism of secular changes of the Earth shape and lithosphere plates tectonics

    NASA Astrophysics Data System (ADS)

    Barkin, Yury

    2010-05-01

    The summary. In the work planetary changes of a figure of the Earth and geoid in present epoch are discussed. Contrast and asymmetric geodetic changes of northern and southern hemispheres are revealed. The phenomenon of lengthening of latitude circles of a southern hemisphere and shortening of lengths of latitude circles of northern hemisphere, the phenomenon of expansion of a southern hemisphere and, accordingly, compression of northern hemisphere in relation to the center of mass of the Earth have been predicted. The reasons of the planetary tendency of displacement (drift) of plates in northern direction are studied. The geodynamic model is developed, on which the basic moving force in tectonics of plates is a gravitational influence of a moveable core of the Earth on all layers of the mantle, and also on blocks of the crust and lithosphere plates. In a base of all tectonic and geological reorganizations the mechanism of the forced relative oscillations and swings of the core and the mantle of the Earth in various time scales, including geological timescale lays. 1 Mechanism of formation and changes of the pear-shaped form of the Earth. According to developed geodynamic model a pear-shaped form of planets is not their given property for all time (as believed before scientists), and is the dynamic response to the slow forced relative displacements of the core and mantle [1]. Than more a relative displacement of the core and mantle (eccentricity of the core in some geology epoch), is especially clearly expressed pear-shaped form. The planet Mars possesses a big pear-shaped form and by our estimations the core of this planet is displaced in northern direction (to latitude in approximately 60° N) on 20-25 km [2]. An eccentricity of the Earth core is less (estimations give displacement about 3-4 km in direction to Brazil [3]) and it pear-shaped form is much less. 2 The phenomenon of asymmetric lengthening of latitude circles of southern and northern hemispheres of

  6. African (Black) Psychology: Issues and Synthesis.

    ERIC Educational Resources Information Center

    Baldwin, Joseph A.

    1986-01-01

    Reviews the recent attempts of Black psychologists and social scientists to formulate a conceptual-operational framework for the study of psychological phenomena as they bear on the cultural-survival conditions of Black-African people. Outlines issues and problems in the attempt to define African (Black) psychology and discusses its relation to…

  7. Genetics Home Reference: African iron overload

    MedlinePlus

    ... of a genetic condition? Genetic and Rare Diseases Information Center Frequency African iron overload is common in rural areas of central and ... more about the gene associated with African iron overload SLC40A1 Related Information What is a gene? What is a gene ...

  8. Multi-stage mountain building vs. relative plate motions in the Betic Cordillera deduced from integrated microstructural and petrological analysis of porphyroblast inclusion trails

    NASA Astrophysics Data System (ADS)

    Aerden, D. G. A. M.; Bell, T. H.; Puga, E.; Sayab, M.; Lozano, J. A.; Diaz de Federico, A.

    2013-03-01

    The tectonic evolution of the Betic Cordillera has been investigated through integrated microstructural and petrological analysis of 93 samples of garnetiferous Grt ± Cld ± Plg ± Ky ± St phengite schists from its lowermost allochthon, the Nevado-Filabride Domain. Porphyroblast inclusion trails in these samples exhibit well-developed preferred vertical and horizontal orientations and truncational relationships. These features indicate a complex history of multiple crenulation cleavage development during alternating contractional and gravity-induced deformations. Associated Foliation-Intersection Axes preserved in porphyroblasts (FIA) were determined separately for 2 groups of samples using the "asymmetry technique" (Bell et al., 1995) and the "FitPitch" method (Aerden, 2003), respectively. Broadly consistent results establish a succession of 4 FIA sets with specific trends, which from the oldest to the youngest FIA set are: NE-SW (FIA set 1), NW-SE (FIA set 2), W-E (FIA set 3) and NNW-SSE (FIA set 4). This trend sequence is also reflected in the orientations of successive fold generations and associated lineations. More remarkably, the FIA-trend sequence mimics known changes in the plate motions of Africa and Adria relative to Iberia in the 50-10 Ma interval. This is also the time span indicated by published radiometric ages. Garnet-isopleth thermobarometry applied to selected samples and compositional zoning of garnets indicate that the earliest 3 FIA sets formed along a prograde metamorphic path from ca. 5 kb/500 °C to 10 kb/550 °C, whereas the latest stages of FIA set 3 and FIA set 4 developed during exhumation. Exhumation involved a period of heterogeneous reheating that was spatially and temporally linked to emplacement of the overlying Alpujarride Complex.

  9. Martian plate tectonics

    NASA Astrophysics Data System (ADS)

    Sleep, N. H.

    1994-03-01

    The northern lowlands of Mars have been produced by plate tectonics. Preexisting old thick highland crust was subducted, while seafloor spreading produced thin lowland crust during late Noachian and Early Hesperian time. In the preferred reconstruction, a breakup margin extended north of Cimmeria Terra between Daedalia Planum and Isidis Planitia where the highland-lowland transition is relatively simple. South dipping subduction occured beneath Arabia Terra and east dipping subduction beneath Tharsis Montes and Tempe Terra. Lineations associated with Gordii Dorsum are attributed to ridge-parallel structures, while Phelegra Montes and Scandia Colles are interpreted as transfer-parallel structures or ridge-fault-fault triple junction tracks. Other than for these few features, there is little topographic roughness in the lowlands. Seafloor spreading, if it occurred, must have been relatively rapid. Quantitative estimates of spreading rate are obtained by considering the physics of seafloor spreading in the lower (approx. 0.4 g) gravity of Mars, the absence of vertical scarps from age differences across fracture zones, and the smooth axial topography. Crustal thickness at a given potential temperature in the mantle source region scales inversely with gravity. Thus, the velocity of the rough-smooth transition for axial topography also scales inversely with gravity. Plate reorganizations where young crust becomes difficult to subduct are another constraint on spreading age. Plate tectonics, if it occurred, dominated the thermal and stress history of the planet. A geochemical implication is that the lower gravity of Mars allows deeper hydrothermal circulation through cracks and hence more hydration of oceanic crust so that more water is easily subducted than on the Earth. Age and structural relationships from photogeology as well as median wavelength gravity anomalies across the now dead breakup and subduction margins are the data most likely to test and modify hypotheses

  10. A web-based survey of horse owners' perceptions and network analysis of horse movements relating to African horse sickness distribution in Namibia and South Africa.

    PubMed

    Liebenberg, Danica; Piketh, Stuart; van Hamburg, Huib

    2016-06-01

    Africa horse sickness (AHS) is the most lethal infectious non-contagious horse disease and has accordingly been declared notifiable by the World Organisation for Animal Health. AHS is endemic to sub-Saharan Africa and causes considerable losses to the equestrian industry. The effect of diseases in livestock on socio-economic factors is well researched, but the effect of anthropogenic factors on the distribution of a disease is poorly understood. The purpose of the study was to assess Namibian and South African horse owners' perceptions and the effect of horse movement on AHS distribution. A cross-sectional study was conducted to collect information from horse owners in Namibia and South Africa. To that end 'Fluid survey' was used for survey development. The survey was launched on Facebook and the link shared to horse related focus groups in Namibia and South Africa. A total of 508 responses were collected during the survey period. Of the 417 completed questionnaires received, 22% were from Namibia and 78% from South Africa. The participants comprised of 71% social and 29% professional riders. The most popular precautionary measures used, in addition to vaccination, were chemical repellents (64%) and stabling of horses during dusk and dawn (59%). A network analysis was performed in Gephi 0.8.2.B to illustrate the movement of horses between countries and districts/provinces. Network analysis results indicate that areas with the highest movement of horses corresponded to the areas with a high occurrence of AHS. Although 93% of the participants were aware that AHS is a notifiable and controlled disease, the process and efficiency of reporting is mostly unknown. With this snapshot of horse owners' perceptions and the effect of horse movement on the distribution of AHS, it is clear that a more holistic approach is needed. To that end, all environmental and social factors must be taken into account in effective management strategies. PMID:26970371

  11. Sexual experiences and condom use of heterosexual, low-income African American and Hispanic youth practicing relative monogamy, serial monogamy, and nonmonogamy.

    PubMed

    Norris, A E; Ford, K

    1999-01-01

    An understanding of differences in contraceptive use patterns among monogamous, serially monogamous, and nonmonogamous adolescents is essential to the design and targeting of condom promotion interventions. Interviews were conducted in Detroit, Michigan (US), in 1991 with a probability sample of 1062 heterosexual, low-income, African American and Hispanic youth 15-24 years of age. 577 were categorized as relatively monogamous, 171 as serially monogamous, and 278 as nonmonogamous. Monogamous youth were most likely to be female, Hispanic, married, and to have engaged in unprotected intercourse. Those who practiced serial monogamy were likely to be younger and to have used condoms at last intercourse. Nonmonogamous youth initiated intercourse earlier, were most likely to have experienced oral and anal intercourse, tended not to use contraception, and had the highest use rates of alcohol and marijuana. Condom use at last intercourse was reported by 38.6% of monogamous youth, 57.3% of the serially monogamous, and 38.2% of nonmonogamous youth; consistent condom use during the past year was reported by only 3.0%, 3.1%, and 2.5%, respectively. Discriminant analysis indicated that age at first intercourse, experience with oral sex, and number of partners best distinguished monogamous youth from serial and nonmonogamous youth. The 3 groups differed significantly in their perceived susceptibility to HIV; 11.0%, 17.8%, and 23.6%, respectively, had ever worried about contracting HIV from a partner. Risk reduction programs should be tailored to accommodate the different needs of these 3 subgroups. For example, nonmonogamous youth tend to be sensation seekers and may be more responsive to condom promotion campaigns that emphasize pleasure enhancement than to fear-based interventions. PMID:9918319

  12. Achievement and Underachievement: The Experiences of African Caribbeans

    ERIC Educational Resources Information Center

    Rhamie, Jasmine

    2012-01-01

    The disproportionate representation of African Caribbeans in all the negative educational statistics has been well documented. Despite this, there are African Caribbeans who achieve academically but relatively few studies have explored this area. This study aimed to investigate the factors that contribute to African Caribbean academic success,…

  13. African American Males in Counseling: Who's Pulling the Trigger Now?

    ERIC Educational Resources Information Center

    Bethea-Whitfield, Patricia

    African American males face numerous challenges to their physical and psychological well-being. This project is a survey of the literature and trends relative to African American males from 1987 to the present. In reviewing the fifteen years since Parham and McDavis published their now famous article on African American men as an endangered…

  14. Perceptions of Discrimination and Achievement in African American Students.

    ERIC Educational Resources Information Center

    Rowley, Stephanie Johnson

    This study explored the processes that lead to relatively lower academic performance among African American students. It has been suggested that African American students perceive that, because of discrimination, education is less useful as a tool for upward mobility for African Americans than it is for members of other ethnic groups. The nature…

  15. Analysis of plate spin motion and its implications for strength of plate boundary

    NASA Astrophysics Data System (ADS)

    Matsuyama, Takeshi; Iwamori, Hikaru

    2016-02-01

    In this study, we investigate the driving forces of plate motion, especially those of plate spin motion, that are related to the toroidal components of the global plate velocity field. In previous works, numerical simulations of mantle convection have been used to examine the extent to which toroidal velocity components are naturally generated on the surface, by varying key parameters, notably the rheological properties of plates and plate boundaries. Here, we take the reverse approach and perform analyses of observed plate motions, which show an increase in the toroidal/poloidal ratio at high degrees of spherical harmonic expansion, as well as a rapid change in the plate spin rate and the estimated driving stress around a critical plate size of approximately 1000 km. This quantitative relationship constrains the strength at plate boundaries to 3-75 MPa, which is consistent with several seismological observations, including those from the NE Japan arc associated with the 2011 Tohoku earthquake.

  16. Cultural aspects of African American eating patterns.

    PubMed

    Airhihenbuwa, C O; Kumanyika, S; Agurs, T D; Lowe, A; Saunders, D; Morssink, C B

    1996-09-01

    The high mortality from diet-related diseases among African Americans strongly suggests a need to adopt diets lower in total fat, saturated fat and salt and higher in fiber. However, such changes would be contrary to some traditional African American cultural practices. Focus group interviews were used to explore cultural aspects of eating patterns among low- and middle-income African Americans recruited from an urban community in Pennsylvania. In total, 21 males and 32 females, aged 13-65+ years were recruited using a networking technique. Participants identified eating practices commonly attributed to African Americans and felt that these were largely independent of socioeconomic status. They were uncertain about links between African American eating patterns and African origins but clear about influences of slavery and economic disadvantage. The perception that African American food patterns were characteristically adaptive to external conditions, suggest that, for effective dietary change in African American communities, changes in the food availability will need to precede or take place in parallel with changes recommended to individuals. Cultural attitudes about where and with whom food is eaten emerged as being equivalent in importance to attitudes about specific foods. These findings emphasize the importance of continued efforts to identify ways to increase the relevance of cultural context and meanings in dietary counseling so that health and nutrition interventions are anchored in values as perceived, in this case, by African Americans. PMID:9395569

  17. African dust outbreaks over the Mediterranean Basin during 2001-2011: PM10 concentrations, phenomenology and trends, and its relation with synoptic and mesoscale meteorology

    NASA Astrophysics Data System (ADS)

    Pey, J.; Querol, X.; Alastuey, A.; Forastiere, F.; Stafoggia, M.

    2013-02-01

    The occurrence of African dust outbreaks over the whole Mediterranean Basin has been studied on an 11-yr period (2001-2011). In order to evaluate the impact of such mineral dust outbreaks on ambient concentrations of particulate matter, PM10 data from regional and suburban background sites across the Mediterranean area were compiled. After identifying the daily influence of African dust, a methodology for the estimation of the natural dust contributions on daily PM10 concentrations was applied. Our findings point out that African dust outbreaks are sensibly more frequent in southern sites across the Mediterranean, from 30 to 37% of the annual days, whereas they occur less than 20% of the annual days in northern sites. The central Mediterranean emerges as a transitional area, with slightly higher frequency of dust episodes in its lower extreme when compared to similar latitudinal positions in western and eastern sides of the Basin. A decreasing south to north gradient of African dust contribution to PM10, driven by the latitudinal position of the monitoring sites at least 25° E westwards across the Basin, is patent across the Mediterranean. As a result of this, an experimental equation for the estimation of annual African dust contributions based on the latitudinal position was obtained. From 25° E eastwards, higher annual dust contributions are encountered due to the elevated annual occurrence of severe episodes of dust but also because of inputs from Negev and Middle Eastern deserts. The slightly higher frequency of African dust episodes observed over southern sites in the central Mediterranean Basin is compensated by its moderately lower intensity. Concerning seasonality patterns and intensity characteristics, a clear summer prevalence is observed in the western part, with low occurrence of severe episodes (daily dust averages over 100 μg m-3 in PM10); no seasonal trend is detected in the central region, with moderate-intensity episodes; and significantly

  18. African dust outbreaks over the Mediterranean Basin during 2001-2011: PM10 concentrations, phenomenology and trends, and its relation with synoptic and mesoscale meteorology

    NASA Astrophysics Data System (ADS)

    Pey, J.; Querol, X.; Alastuey, A.; Forastiere, F.; Stafoggia, M.

    2012-10-01

    The occurrence of African dust outbreaks over the whole Mediterranean Basin has been identified on an 11-yr period (2001-2011). In order to evaluate the impact of such mineral dust outbreaks on ambient concentrations of particulate matter, PM10 data from regional and suburban background sites across the Mediterranean area were compiled. After identifying the daily influence of African dust, a methodology for estimating natural dust contributions on daily PM10 concentrations was applied. Our results reveal that African dust outbreaks occur with much higher frequency in southern areas of the Mediterranean, from 30 to 37% of the annual days, whereas they take place less than 20% of the annual days in northern sites. The central Mediterranean emerges as a transitional area, with slightly higher frequency of dust episodes in its lower extreme when compared to equivalent areas in western and eastern sides of the Basin. A decreasing south to north gradient of African dust contribution to PM10 is patent across the Mediterranean. Our study demonstrates that this gradient may be mainly explained by the latitudinal position. A longitudinal increasing trend of African dust contribution to PM10 is also observed from 25° E eastwards, and is due to the annual occurrence of intense dust episodes. Thus, the slightly higher frequency of African dust episodes over the lower part of Central Mediterranean is compensated by its moderately lower intensity. Concerning seasonality patterns and intensity characteristics, a clear summer prevalence is observed in the western part, with low occurrence of severe episodes (daily dust averages over 100 μg m-3 in PM10); no seasonal trend is detected in the central region, with moderate-intensity episodes; and significantly higher contributions are common in autumn-spring in the eastern side, with yearly occurrence of various severe episodes. Overall, African dust emerges as the largest PM10 source in regional background southern areas of the

  19. Summary of the stratigraphy and structural elements related to plate convergence of the Quetta-Muslim Bagh-Sibi region, Balochistan, west-central Pakistan

    USGS Publications Warehouse

    Maldonado, Florian; Mengal, Jan M.; Khan, Shahid H.; Warwick, Peter D.

    2011-01-01

    The four major faults that bound the structural terrane are the Frontal (F), Ghazaband-Zhob (GZ), Gwal-Bagh (GB), and Chaman (C) faults. Four major periods of deformation are recognized: (1) emplacement of ophiolitic rocks onto the continental margin of the India plate; (2) convergence of the India-Eurasia plates; (3) deposition of Tertiary-Quaternary molasse units followed by major folding and thrusting, and formation of strike-slip faults; and (4) deposition of Pleistocene molasse units with subsequent folding, thrusting, and strike-slip motion that continues to the present.

  20. Geomorphometric reconstruction of post-eruptive surfaces of the Virunga Volcanic Province (East African Rift), constraint of erosion ratio and relative chronology

    NASA Astrophysics Data System (ADS)

    Lahitte, Pierre; Poppe, Sam; Kervyn, Matthieu

    2016-04-01

    Quaternary volcanic landforms result from a complex evolution, involving volcanic constructional events and destructive ones by collapses and long-term erosion. Quantification, by morphometric approaches, of the evolution through time of the volcano shape allows the estimation of relative ages between volcanoes sharing the same climate and eruptive conditions. We apply such method to six volcanoes of the Virunga Volcanic Province in the western branch of the East African Rift Valley that still has rare geochronological constraints. As they have comparable sizes, volcanic history and erupted products, these edifices may have undergone comparable conditions of erosion which justify the deduction of relative chronology from their erosion pattern. Our GIS-based geomorphometric approach, the SHAPEVOLC algorithm, quantifies erupted or dismantled volumes by numerically modeling topographies resulting from the eruptive construction of each volcano. Constraining points are selected by analyses of morphometric properties of each cell of the current DEM, as the loci where the altitude is still representative of the un-eroded volcanic surfaces. A primary elevation surface is firstly adjusted to these constraining points by modeling a first-order pseudo-radial surface defined by: 1. the curve best fitting the concave-upwards volcano profile; 2. the location and elevation of the volcano summit; and 3. the possible eccentricity and azimuth parameters that allow to stretch and contract contours to adjust the shape of the model to the elliptically-shaped surface of the volcano. A second-order surface is next computed by local adjustment of the first-order surface to the constraining points to obtain the definitive primary elevation surface of the considered volcanic construct. Amount of erosion is obtained by summing the difference in elevation between reconstructed surfaces and current ones that allows to establish relative ages of volcanoes. For the 6 studied Virunga volcanoes

  1. How is Silurian-Early Devonian faulting in the North America continental interior related to orogenic processes at plate boundaries? A working hypothesis from the Canadian North

    NASA Astrophysics Data System (ADS)

    Pinet, Nicolas

    2015-04-01

    The Paleozoic Appalachian/Franklinian orogen that rims the North America continent on its eastern and northern sides is comparable in size with Tethyan orogenic belts. However, the far-field effects in the continental interior of the multiple Ordovician to Carboniferous deformation phases that built the orogen were relatively minor if compared with those associated with the Himalayas and Alps, a characteristics related to the high integrated strength of the North American craton. Despite the generally little deformation of the continental interior, two regional-scale tectonic features preserved evidence of significant Paleozoic tectonism: the fault bounded Hudson Bay Central High (HBCH) and the Boothia uplift/Cornwallis fold belt (BUCF) in the Canadian Arctic. In the Hudson Bay intracratonic basin, the lower part of the sedimentary succession (Upper Ordovician to Lower Devonian) is cut by high-angle faults and overlain by a saucer-shape, essentially underformed sedimentary package (Middle to Upper Devonian). The main structural feature is the NNW-trending HBCH that extends for a minimum length of 500 km with normal faults characterized by throws up to 500 m that were mainly active during the Silurian - Early Devonian period. The >700-km long, N-trending BUCF is nearly perpendicular to the deformation front of the Franklinian mobile belt. In its southern segment (Boothia uplift), its western side is characterized by an east-dipping reverse fault zone that puts Precambrian rocks over Paleozoic strata. In its northern segment (Cornwallis fold belt), the Paleozoic succession is involved in open folds and cuts by steeply dipping reverse faults. Syn-tectonic clastic sediments constrain the age of structures to the latest Silurian-Early Devonian. Comparison of the HBCH and BUCF indicates that they are grossly parallel, partly contemporaneous but with different kinematics. This kinematic variability may be explained if they are genetically linked with different segments of

  2. Current global plate kinematics from GPS (1995-2007) with the plate-consistent reference frame

    NASA Astrophysics Data System (ADS)

    Kogan, Mikhail G.; Steblov, Grigory M.

    2008-04-01

    We present the vectors of rotation of 10 major lithospheric plates, estimated from continuous GPS observations at 192 globally distributed stations; 71 stations were selected as representing stable plate regions. All days for the period 1995.0-2007.0 were included in the analysis. In contrast to previous GPS plate models, our model is independent of international terrestrial reference frames (ITRF). The origin of our plate-consistent reference frame is the center of plate rotation (CP) rather than the center of mass of the entire Earth's system (CM) as in recent versions of ITRF. We estimate plate rotations and CP by minimizing the misfit between the horizontal velocities predicted by the plate model and the observed GPS velocities. If any version of ITRF is used as the reference frame, the drift of the ITRF origin relative to CP cannot be neglected in estimation of plate rotation vectors and plate-residual station velocities. The model of the plate kinematics presented here addresses the problem debated since the beginning of the space geodesy: how big are disagreements between the current plate motions and the motions averaged over several million years? We compare the vectors of relative plate rotations estimated here with the published vectors from GPS and geologic models. We also discuss the integrity of individual plates as exhibited by plate-residual station velocities. For seven largest plates, the RMS value of plate-residual station velocities in stable plate interiors is 0.5-0.9 mm/a; this value is an upper bound on deviation of real plates from infinite stiffness.

  3. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  4. Self Regulated and Communal Learning Contexts as They Relate to Math Achievement and Math Self Efficacy among African American Elementary Level Students

    ERIC Educational Resources Information Center

    Jackson, Shirley Faye Jackson

    2012-01-01

    For decades, African American students, nationwide, have consistently scored much lower on math and reading achievement tests than their European counterparts, creating what is known as the "White-Black Achievement Gap". The purpose of the research was to determine if self regulated learning and communal learning contexts, either…

  5. Explaining Disproportionately High Rates of Adverse Birth Outcomes among African Americans: The Impact of Stress, Racism, and Related Factors in Pregnancy

    ERIC Educational Resources Information Center

    Giscombe, Cheryl L.; Lobel, Marci

    2005-01-01

    Compared with European Americans, African American infants experience disproportionately high rates of low birth weight and preterm delivery and are more than twice as likely to die during their 1st year of life. The authors examine 5 explanations for these differences in rates of adverse birth outcomes: (a) ethnic differences in health behaviors…

  6. Factors Related to Self-Esteem among African American Youths: A Secondary Analysis of the High/Scope Perry Preschool Data.

    ERIC Educational Resources Information Center

    Luster, Tom; McAdoo, Harriette Pipes

    1995-01-01

    Used Perry Preschool data on 121 African American adolescents to explore correlates of self-esteem. Higher self-esteem scores were expected for youths who had experienced success in areas important to them and who perceived that significant others regarded them highly. Data supported the hypothesis that the effects of teens' accomplishments and…

  7. A Comparative Analysis Regarding Factors Related to 13- to 18-Year-Old African American Male Adolescents in Special Education and the Justice System

    ERIC Educational Resources Information Center

    Phipps, Jonathan Lanier

    2013-01-01

    This study was focused on the identification of selected risk factors seemingly present among African American male adolescents 13 to 18 years old who were participants in special education programs at their schools. Many of these male adolescents were also found to participate in the juvenile justice system under what was characterized as…

  8. National Cry for Help: Psychological Issues as They Relate to Education; A Realistic Approach to Understanding and Coping with the African American Males

    ERIC Educational Resources Information Center

    Anthony, Taiwanna D.; Kritsonis, William Allan; Herrington, David E.

    2007-01-01

    One could argue that advance teacher training does not make a difference in student achievement. According to William Sanders, a Professor at the University of Tennessee, the single most dominate factor affecting student achievement gain is teachers advance training. African American students make up 17 percent of the public school population…

  9. Frederick Douglass and I: Writing to Read and Relate History with Life among African American Adolescents at a High-Poverty Urban School

    ERIC Educational Resources Information Center

    Morphy, Paul

    2013-01-01

    Purpose: Black history as represented in social studies textbooks often lacks depth demanded by historians and authenticity required for cultural relevance to African American students. However, important Black historical narratives sometimes contain difficult prose and refer to times or circumstances that are far removed from students' life…

  10. Difficulties encountered removing locked plates

    PubMed Central

    Raja, S; Imbuldeniya, AM; S, Garg; Groom, G

    2012-01-01

    INTRODUCTION Locked plates are commonly used to obtain fixation in periarticular and comminuted fractures. Their use has also gained popularity in repairing fractures in osteoporotic bone. These plates provide stable fixation and promote biological healing. Over the last 3 years, we have used over 150 locked plates with varying success to fix periarticular fractures involving mainly the knee and ankle. In this study, we report our clinical experience and the difficulties encountered when removing locked plates in adult patients with a variety of indications including implant failure, infection, non-union and a palpable symptomatic implant. METHODS A retrospective analysis was performed of patients enrolled prospectively into a database. Included in the study were 36 consecutive adult patients who each underwent the procedure of locked plate removal in a single inner city level 1 trauma centre. Data collected included primary indication for fixation, indication for implant removal, time of the implant in situ, grade of operating surgeon and difficulties encountered during the procedure. RESULTS Implant removal was associated with a complication rate of 47%. The major problems encountered were difficulty in removing the locked screws and the implant itself. A total of ten cold welded screws were found in eight cases. Removal was facilitated by high speed metal cutting burrs and screw removal sets in all but one case, where a decision was made to leave the plate in situ. CONCLUSIONS The majority of studies investigating implant removal and problems encountered in doing so report a relatively high complication rate. With the advent of locking plates and their growing popularity, difficulties are now being seen intra-operatively when removing them. There is a paucity of data, however, specifically directed at locking plate removal. We recommend that surgeons should be aware of the potential complications while removing locked plates. Fluoroscopic control and all

  11. Plate motion and deformation

    SciTech Connect

    Minster, B.; Prescott, W.; Royden, L.

    1991-02-01

    Our goal is to understand the motions of the plates, the deformation along their boundaries and within their interiors, and the processes that control these tectonic phenomena. In the broadest terms, we must strive to understand the relationships of regional and local deformation to flow in the upper mantle and the rheological, thermal and density structure of the lithosphere. The essential data sets which we require to reach our goal consist of maps of current strain rates at the earth's surface and the distribution of integrated deformation through time as recorded in the geologic record. Our success will depend on the effective synthesis of crustal kinematics with a variety of other geological and geophysical data, within a quantitative theoretical framework describing processes in the earth's interior. Only in this way can we relate the snapshot of current motions and earth structure provided by geodetic and geophysical data with long-term processes operating on the time scales relevant to most geological processes. The wide-spread use of space-based techniques, coupled with traditional geological and geophysical data, promises a revolution in our understanding of the kinematics and dynamics of plate motions over a broad range of spatial and temporal scales and in a variety of geologic settings. The space-based techniques that best address problems in plate motion and deformation are precise space-geodetic positioning -- on land and on the seafloor -- and satellite acquisition of detailed altimetric and remote sensing data in oceanic and continental areas. The overall science objectives for the NASA Solid Earth Science plan for the 1990's, are to Understand the motion and deformation of the lithosphere within and across plate boundaries'', and to understand the dynamics of the mantle, the structure and evolution of the lithosphere, and the landforms that result from local and regional deformation. 57 refs., 7 figs., 2 tabs.

  12. The African Pediatric Fellowship Program: Training in Africa for Africans.

    PubMed

    Wilmshurst, Jo M; Morrow, Brenda; du Preez, Avril; Githanga, David; Kennedy, Neil; Zar, Heather J

    2016-01-01

    Africa has a significant burden of childhood disease, with relatively few skilled health care professionals. The African Paediatric Fellowship Programme was developed by the Department of Pediatrics and Child Health at the University of Cape Town to provide relevant training for African child health professionals, by Africans, within Africa. Trainees identified by partner academic institutions spend 6 months to 2 years training in the Department of Pediatrics and allied disciplines. They then return to their home institution to build practice, training, research, and advocacy. From 2008 to 2015, 73 physicians have completed or are completing training in general pediatrics or a pediatric subspecialty. At 1 year posttraining, 98% to 100% are practicing back in their home institution. The impact of the returning fellows is evident from their practice interventions, research collaborations, and positions as stakeholders who can change health care policies. Thirty-three centers in 13 African countries are partners with the program, and the program template is now followed by other partner sites in Africa. Increasing and retaining the skills pool of African child health specialists is building a network of motivated, highly skilled clinicians who are equipped to advance child health in Africa. PMID:26659458

  13. In situ rutile petrochronology: texture-related T, Paleoproterozoic inheritance and a Pan-African overprint in the oldest subduction-related eclogites, Usagaran Orogen, Tanzania

    NASA Astrophysics Data System (ADS)

    Moeller, A.; Kraus, K.; Herms, P.; Appel, P.; Raase, P.

    2014-12-01

    Rutile U-Pb thermochronology is applied successfully by both TIMS and beam methods to date cooling events in mafic and metapelitic rocks, as well as in detrital studies. The Zr-in-rutile thermometer is very robust to thermal diffusion, and generally requires complete recrystallization to change recorded crystallization temperatures. Evidence for diffusion of HFSE elements in rutile is sparse; whereas U-Pb chronology generally records diffusion controlled cooling from the last event. This study follows conventional thermobarometry and U-Pb TIMS results on monazite, sphene and rutile of Möller et al. (1995) establishing a 2 Ga eclogite facies event from MORB-like metabasic, and metapelitic rocks in the Usagaran Orogen of Tanzania, interpreted to be the oldest outcrops of subduction-related eclogites. Rutile from both rock types were discordant near a ca. 500 Ma lower intercept, confirming a thermal overprint postulated on the basis of K-Ar and Rb-Sr mica ages by e.g. Wendt et al. (1972). The age of the eclogite-facies event was confirmed by U-Pb zircon dating of a 1991±2 Ma crosscutting pegmatite (Collins et al., 1999). We present in situ LA-ICP-MS rutile petrochronology on five metabasic and metapelitic eclogite facies samples with variable retrograde amphibolite-facies recrystallization. Thermometry confirms conventional Fe-Mg results, including higher peak temperatures in metabasites. Traverses on rutile inclusions in large garnet prophyroblasts in metapelites show increasing temperatures from cores outwards and a slight decrease towards outermost rims, with peak T coinciding with highest Mg# and highest grossular content, hence consistent with preservation of prograde zoning in the garnets and a brief eclogite facies event. Large rutiles (800μm) in recrystallized samples record temperature zoning profiles. U-Pb results show inheritance of near concordant 2 Ga domains, but dominantly confirm the ca. 490 Ma amphibolite facies overprint. The study is an excellent

  14. Quaternions as astrometric plate constants

    NASA Technical Reports Server (NTRS)

    Jefferys, William H.

    1987-01-01

    A new method for solving problems in relative astrometry is proposed. In it, the relationship between the measured quantities and the components of the position vector of a star is modeled using quaternions, in effect replacing the plate constants of a standard four-plate-constant solution with the four components of a quaternion. The method allows a direct solution for the position vectors of the stars, and hence for the equatorial coordinates. Distortions, magnitude, and color effects are readily incorporated into the formalism, and the method is directly applicable to overlapping-plate problems. The advantages of the method include the simplicity of the resulting equations, their freedom from singularities, and the fact that trigonometric functions and tangential point transformations are not needed to model the plate material. A global solution over the entire sky is possible.

  15. China's Recruitment of African University Students: Policy Efficacy and Unintended Outcomes

    ERIC Educational Resources Information Center

    Haugen, Heidi Østbø

    2013-01-01

    This article explores how Sino-African relations are affected by the growing number of Africans who pursue higher education in China. China actively recruits African university students in order to increase soft power and generate income from the export of education services. Semi-structured interviews with African university students suggest that…

  16. The African Cultural Astronomy Project

    NASA Astrophysics Data System (ADS)

    Urama, Johnson O.; Holbrook, Jarita C.

    2011-06-01

    Indigenous, endogenous, traditional, or cultural astronomy focuses on the many ways that people and cultures interact with celestial bodies. In most parts of Africa, there is very little or no awareness about modern astronomy. However, like ancient people everywhere, Africans wondered at the sky and struggled to make sense of it. The African Cultural Astronomy Project aims to unearth the body of traditional knowledge of astronomy possessed by peoples of the different ethnic groups in Africa and to consider scientific interpretations when appropriate for cosmogonies and ancient astronomical practices. Regardless of scientific validity, every scientist can relate to the process of making observations and creating theoretical mechanisms for explaining what is observed. Through linking the traditional and the scientific, it is believed that this would be used to create awareness and interest in astronomy in most parts of Africa. This paper discusses the vision, challenges and prospects of the African Cultural Astronomy Project in her quest to popularize astronomy in Africa.

  17. Black African Traditional Mathematics

    ERIC Educational Resources Information Center

    Zaslavsky, Claudia

    1970-01-01

    Discusses the traditional number systems and the origin of the number names used by several African peoples living south of the Sahara. Also included are limitations in African mathematical development, and possible topics for research. (RP)

  18. Informing cancer prevention strategies for African Americans: the relationship of African American acculturation to fruit, vegetable, and fat intake.

    PubMed

    Ard, Jamy D; Skinner, Celette Sugg; Chen, Chuhe; Aickin, Mikel; Svetkey, Laura P

    2005-06-01

    Acculturation has been associated with health-related behaviors in African Americans. We sought to determine if there is a relationship between acculturation and dietary intake in African Americans. African Americans in the PREMIER trial completed the African American Acculturation Scale (AAAS) and 2 nonconsecutive 24-h dietary recalls (n = 238). Analysis of variance (ANOVA) and canonical correlation were used to assess relationships between acculturation and dietary intakes. Canonical correlation (p = 0.05) showed that traditional African Americans had lower intakes of fruits/vegetables and milk/dairy with higher intakes of fats, meat, and nuts. This pattern was supported by differences in the ANOVA. African American acculturation is related to dietary intake. These findings have implications for the design of cancer-related public health messages targeted to African Americans. PMID:16015458

  19. Suicidal behavior in black South Africans.

    PubMed

    Schlebusch, Lourens; Vawda, Naseema B M; Bosch, Brenda A

    2003-01-01

    In the past suicidal behavior among Black South Africans has been largely underresearched. Earlier studies among the other main ethnic groups in the country showed suicidal behavior in those groups to be a serious problem. This article briefly reviews some of the more recent research on suicidal behavior in Black South Africans. The results indicate an apparent increase in suicidal behavior in this group. Several explanations are offered for the change in suicidal behavior in the reported clinical populations. This includes past difficulties for all South Africans to access health care facilities in the Apartheid (legal racial separation) era, and present difficulties of post-Apartheid transformation the South African society is undergoing, as the people struggle to come to terms with the deleterious effects of the former South African racial policies, related socio-cultural, socio-economic, and other pressures. PMID:12809149

  20. Impact on multilayered composite plates

    NASA Technical Reports Server (NTRS)

    Kim, B. S.; Moon, F. C.

    1977-01-01

    Stress wave propagation in a multilayer composite plate due to impact was examined by means of the anisotropic elasticity theory. The plate was modelled as a number of identical anisotropic layers and the approximate plate theory of Mindlin was then applied to each layer to obtain a set of difference-differential equations of motion. Dispersion relations for harmonic waves and correction factors were found. The governing equations were reduced to difference equations via integral transforms. With given impact boundary conditions these equations were solved for an arbitrary number of layers in the plate and the transient propagation of waves was calculated by means of a Fast Fourier Transform algorithm. The multilayered plate problem was extended to examine the effect of damping layers present between two elastic layers. A reduction of the interlaminar normal stress was significant when the thickness of damping layer was increased but the effect was mostly due to the softness of the damping layer. Finally, the problem of a composite plate with a crack on the interlaminar boundary was formulated.

  1. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  2. Provenance change of sediment input in the northeastern foreland of Pamir related to collision of the Indian Plate with the Kohistan-Ladakh arc at around 47 Ma

    NASA Astrophysics Data System (ADS)

    Sun, Jimin; Xiao, Wenjiao; Windley, Brian F.; Ji, Weiqiang; Fu, Bihong; Wang, Jiangang; Jin, Chunsheng

    2016-02-01

    The Pamir plateau forms a prominent tectonic salient that marks the western end of the Himalayan orogen containing several terranes that were accreted to Eurasia from the Late Paleozoic to Cenozoic. A detailed knowledge of the tectonic evolution of the Pamir salient during the Cenozoic is important for our understanding of the intracontinental deformation in the western Himalaya. Although the tectonic evolution of the Pamir salient has long been studied, the timing of collision between the Indian Plate and the Kohistan-Ladakh arc is still a matter of debate. We present new U-Pb ages and Hf isotopes of detrital zircons, magnetic fabrics, and stable isotopes from the foreland basin on the northeastern margin of the Pamir that indicate a change in sediment provenance started at about 47 Ma. Sediments in the southwest Tarim Basin were partially derived from the uplifted and eroded Karakoram and Kohistan terranes created by the collision between the Indian Plate and the Kohistan-Ladakh arc at circa 47 Ma, as a result of northward thrusting and propagation of the Indian Plate under Eurasia.

  3. A Comparison of Phenotypic Traits Related to Trypanotolerance in Five West African Cattle Breeds Highlights the Value of Shorthorn Taurine Breeds

    PubMed Central

    Berthier, David; Peylhard, Moana; Dayo, Guiguigbaza-Kossigan; Flori, Laurence; Sylla, Souleymane; Bolly, Seydou; Sakande, Hassane; Chantal, Isabelle; Thevenon, Sophie

    2015-01-01

    Background Animal African Trypanosomosis particularly affects cattle and dramatically impairs livestock development in sub-Saharan Africa. African Zebu (AFZ) or European taurine breeds usually die of the disease in the absence of treatment, whereas West African taurine breeds (AFT), considered trypanotolerant, are able to control the pathogenic effects of trypanosomosis. Up to now, only one AFT breed, the longhorn N’Dama (NDA), has been largely studied and is considered as the reference trypanotolerant breed. Shorthorn taurine trypanotolerance has never been properly assessed and compared to NDA and AFZ breeds. Methodology/Principal Findings This study compared the trypanotolerant/susceptible phenotype of five West African local breeds that differ in their demographic history. Thirty-six individuals belonging to the longhorn taurine NDA breed, two shorthorn taurine Lagune (LAG) and Baoulé (BAO) breeds, the Zebu Fulani (ZFU) and the Borgou (BOR), an admixed breed between AFT and AFZ, were infected by Trypanosoma congolense IL1180. All the cattle were genetically characterized using dense SNP markers, and parameters linked to parasitaemia, anaemia and leukocytes were analysed using synthetic variables and mixed models. We showed that LAG, followed by NDA and BAO, displayed the best control of anaemia. ZFU showed the greatest anaemia and the BOR breed had an intermediate value, as expected from its admixed origin. Large differences in leukocyte counts were also observed, with higher leukocytosis for AFT. Nevertheless, no differences in parasitaemia were found, except a tendency to take longer to display detectable parasites in ZFU. Conclusions We demonstrated that LAG and BAO are as trypanotolerant as NDA. This study highlights the value of shorthorn taurine breeds, which display strong local adaptation to trypanosomosis. Thanks to further analyses based on comparisons of the genome or transcriptome of the breeds, these results open up the way for better knowledge

  4. Research with African Americans: Lessons Learned about Recruiting African American Women

    ERIC Educational Resources Information Center

    Coker, Angela D.; Huang, Hsin-Hsin; Kashubeck-West, Susan

    2009-01-01

    The authors briefly explore literature related to recruiting African American research participants, reflect on their experiences conducting body image research with a sample of African American college women in an earlier study (S. Kashubeck-West et al., 2008), and discuss some methodological and cultural challenges that they encountered during…

  5. Changing Fatherhood: An Exploratory Qualitative Study with African and African Caribbean Men in England

    ERIC Educational Resources Information Center

    Williams, Robert; Hewison, Alistair; Wildman, Stuart; Roskell, Carolyn

    2013-01-01

    This paper presents findings from a qualitative study undertaken with 46 African and African Caribbean men exploring their experiences of fatherhood. Data analysis was informed by Connell's theoretical work on changing gender relations. Findings indicate that fathers' lives were mediated by masculinities, racism, gender, migration and…

  6. Teaching African American Youth: Learning from the Lives of Three African American Social Studies Teachers

    ERIC Educational Resources Information Center

    McBride, Chantee Earl

    2010-01-01

    This study examines the life histories of three African American social studies teachers, focusing on the evolution and changes in their identities, perspectives, and attitudes related to their profession and instructional practice. In addition, the study addresses the significance of the teachers' racialized experiences as African Americans and…

  7. Tethyan collision forces and the stress field of the Eurasian Plate

    NASA Astrophysics Data System (ADS)

    Warners-Ruckstuhl, Karin N.; Govers, Rob; Wortel, Rinus

    2013-10-01

    Resistive forces along convergent plate boundaries have a major impact on surface deformation, most visibly at collisional plate boundaries. Although quantification of these forces is key to understanding the evolution and present state of mountain belts, they remain highly uncertain due to the complexity of plate boundary structures and rheologies. In previous studies of the Eurasian Plate, we have analysed the balance of plate boundary forces, tractions resulting from lithosphere-mantle coupling, and intraplate variations in topography and density structure. This yielded a range of acceptable force distributions. In this study, we investigate to which extent the observed present-day stress field provides further constraints on the distribution of forces. We address the dynamics of the Eurasian Plate as a whole. This enables us to base our analysis on mechanical equilibrium of a tectonic plate and to evaluate all forces as part of an internally consistent set of forces driving and deforming Eurasia. We incorporate tractions from convective mantle flow modelling in a lithospheric model in which edge and lithospheric body forces are modelled explicitly and compute resulting stresses in a homogeneous elastic thin shell. Intraplate stress observations used are from the World Stress Map project. Eurasia's stress field turns out to be particularly sensitive to the distribution of collision forces on the plate's southern margin and, to a much lesser extent, to lithospheric density structure and tractions from mantle flow. Stress observations require collision forces on the India-Eurasia boundary of 7.0-10.5 TN m-1 and on the Arabia-Eurasia boundary of 1.3-2.7 TN m-1. Implication of mechanical equilibrium of the plate is that forces on the contacts with the African and Australian plates amount to 1.0-2.5 and 0-1.3 TN m-1, respectively. We use our results to assess the validity of the classical view that the mean elevation of an orogenic plateau can be taken as a measure

  8. An understanding of HSLA-65 plate steels

    NASA Astrophysics Data System (ADS)

    Sampath, K.

    2006-02-01

    HSLA-65 plate steels can be produced using one of five plate manufacturing techniques: normalizing, controlled rolling (CR), controlled rolling followed by accelerated cooling (CR-AC), direct quenching and tempering (DQT), or conventional quenching and tempering (Q&T). The HSLA-65 steels are characterized by low carbon content and low alloy content, and they exhibit a low carbon equivalent that allows improved plate weldability. These characteristics in turn (a) provide the steel plate with a refined microstructure that ensures high strength and toughness; (b) eliminate or substantially reduce the need for preheating during welding; (c) resist susceptibility to hydrogen-assisted cracking (HAC) in the weld heat affected zone (HAZ) when fusion (arc) welded using low heat-input conditions; and (d) depending on section thickness, facilitate high heat-input welding (about 2 kJ/mm) without significant loss of strength or toughness in the HAZ. However, application of this plate manufacturing process and of these controls produces significant differences in the metallurgical structure and range of mechanical properties of the HSLA-65 plate steels both among themselves and versus conventional higher strength steel (HSS) plates. For example, among the HSLA-65 plate steels, those produced by Q&T exhibit minimal variability in mechanical properties, especially in thicker plates. Besides variability in mechanical properties depending on plate thickness, the CR and CR-AC plate steels exhibit a relatively higher yield strength to ultimate tensile strength (YS/UTS) ratio than do DQT and Q&T steels. Such differences in processing and properties of HSLA-65 plate steels could potentially affect the selection and control of various secondary fabrication practices, including arc welding. Consequently, fabricators must exercise extreme caution when transferring allowable limits of certified secondary fabrication practices from one type of HSLA-65 plate steel to another, even for the

  9. Using the Mesozoic History of the Canadian Cordillera as a Case Study in Teaching Plate Tectonics.

    ERIC Educational Resources Information Center

    Chamberlain, Valerie Elaine

    1989-01-01

    Reviews a model used in the teaching of plate tectonics which includes processes and concepts related to: terranes and the amalgamation of terranes, relative plate motion and oblique subduction, the effects of continent-continent collision, changes in plate motion, plate configuration, and the type of plate boundary. Diagrams are included.…

  10. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  11. Incorporating Cutting Edge Scientific Results from the Margins-Geoprisms Program into the Undergraduate Curriculum, Rupturing Continental Lithosphere Part II: Introducing Euler Poles Using Baja-North America Relative Plate Motion Across the Gulf of California

    NASA Astrophysics Data System (ADS)

    Loveless, J. P.; Bennett, S. E. K.; Cashman, S. M.; Dorsey, R. J.; Goodliffe, A. M.; Lamb, M. A.

    2014-12-01

    The NSF-MARGINS Program funded a decade of research on continental margin processes. The NSF-GeoPRISMS Mini-lesson Project, funded by NSF-TUES, is designed to integrate the significant findings from the MARGINS program into open-source college-level curriculum. The Gulf of California (GOC) served as the focus site for the Rupturing Continental Lithosphere (RCL) initiative, which addressed several scientific questions: What forces drive rift initiation, localization, propagation and evolution? How does deformation vary in time and space, and why? How does crust evolve, physically and chemically, as rifting proceeds to sea-floor spreading? What is the role of sedimentation and magmatism in continental extension? We developed two weeks of curriculum, including lectures, labs, and in-class activities that can be used as a whole or individually. This component of the curriculum introduces students to the Euler pole description of relative plate motion (RPM) by examining the tectonic interactions of the Baja California microplate and North American plate. The plate boundary varies in rift obliquity along strike, from highly oblique and strike-slip dominated in the south to slightly less oblique and with a larger extensional component in the north. This Google Earth-based exercise provides students with a visualization of RPM using small circle contours of the local direction and magnitude of Baja-North America movement on a spherical Earth. Students use RPM to calculate the fault slip rates on transform, normal, and oblique-slip faults and examine how the varying faulting styles combine to accommodate RPM. MARGINS results are integrated via comparison of rift obliquity with the structural style of rift-related faults around the GOC. We find this exercise to fit naturally into courses about plate tectonics, geophysics, and especially structural geology, given the similarity between Euler pole rotations and stereonet-based rotations of structural data.

  12. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  13. Closure of the Africa-Eurasia-North America plate motion circuit and tectonics of the Gloria fault

    NASA Technical Reports Server (NTRS)

    Argus, Donald F.; Gordon, Richard G.; Demets, Charles; Stein, Seth

    1989-01-01

    The current motions of the African, Eurasian, and North American plates are examined. The problems addressed include whether there is resolvable motion of a Spitsbergen microplate, the direction of motion between the African and North American plates, whether the Gloria fault is an active transform fault, and the implications of plate circuit closures for rates of intraplate deformation. Marine geophysical data and magnetic profiles are used to construct a model which predicts about 4 mm/yr slip across the Azores-Gibraltar Ridge, and west-northwest convergence near Gibraltar. The analyzed data are consistent with a rigid plate model with the Gloria fault being a transform fault.

  14. Plating Tank Control Software

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  15. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  16. Bioenergy and African transformation.

    PubMed

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures. PMID:25709714

  17. Beyond plate tectonics - Looking at plate deformation with space geodesy

    NASA Technical Reports Server (NTRS)

    Jordan, Thomas H.; Minster, J. Bernard

    1988-01-01

    The requirements that must be met by space-geodetic systems in order to constrain the horizontal secular motions associated with the geological deformation of the earth's surface are explored. It is suggested that in order to improve existing plate-motion models, the tangential components of relative velocities on interplate baselines must be resolved to an accuracy of less than 3 mm/yr. Results indicate that measuring the velocities between crustal blocks to + or - 5 mm/yr on 100-km to 1000-km scales can produce geologically significant constraints on the integrated deformation rates across continental plate-boundary zones such as the western United States.

  18. Socioeconomic Status in Relation to the Risk of Ovarian Cancer in African-American Women: A Population-Based Case-Control Study.

    PubMed

    Alberg, Anthony J; Moorman, Patricia G; Crankshaw, Sydnee; Wang, Frances; Bandera, Elisa V; Barnholtz-Sloan, Jill S; Bondy, Melissa; Cartmell, Kathleen B; Cote, Michelle L; Ford, Marvella E; Funkhouser, Ellen; Kelemen, Linda E; Peters, Edward S; Schwartz, Ann G; Sterba, Katherine Regan; Terry, Paul; Wallace, Kristin; Schildkraut, Joellen M

    2016-08-15

    We investigated the association between socioeconomic status and ovarian cancer in African-American women. We used a population-based case-control study design that included case patients with incident ovarian cancer (n = 513) and age- and area-matched control participants (n = 721) from 10 states who were recruited into the African American Cancer Epidemiology Study from December 2010 through December 2014. Questionnaires were administered via telephone, and study participants responded to questions about several characteristics, including years of education, family annual income, and risk factors for ovarian cancer. After adjustment for established ovarian cancer risk factors, women with a college degree or more education had an odds ratio of 0.71 (95% confidence interval (CI): 0.51, 0.99) when compared with those with a high school diploma or less (P for trend = 0.02); women with family annual incomes of $75,000 or more had an odds ratio of 0.74 (95% CI: 0.47, 1.16) when compared with those with incomes less than $10,000 (P for trend = 0.055). When these variables were dichotomized, compared with women with a high school diploma or less, women with more education had an adjusted odds ratio of 0.72 (95% CI: 0.55, 0.93), and compared with women with an income less than $25,000, women with higher incomes had an adjusted odds ratio of 0.86 (95% CI: 0.66, 1.12). These findings suggest that ovarian cancer risk may be inversely associated with socioeconomic status among African-American women and highlight the need for additional evidence to more thoroughly characterize the association between socioeconomic status and ovarian cancer. PMID:27492896

  19. Gene-based analysis of the fibroblast growth factor receptor signaling pathway in relation to breast cancer in African American women: the AMBER consortium.

    PubMed

    Ruiz-Narváez, Edward A; Haddad, Stephen A; Lunetta, Kathryn L; Yao, Song; Bensen, Jeannette T; Sucheston-Campbell, Lara E; Hong, Chi-Chen; Haiman, Christopher A; Olshan, Andrew F; Ambrosone, Christine B; Palmer, Julie R

    2016-01-01

    We conducted gene-based analysis in 26 genes in the FGFR signaling pathway to identify genes carrying genetic variation affecting risk of breast cancer and the specific estrogen receptor (ER) subtypes. Tagging single-nucleotide polymorphisms (SNPs) for each gene were selected and genotyped on a customized Illumina Exome Array. Imputation was carried out using 1000 Genomes haplotypes. The analysis included 3237 SNPs in 3663 breast cancer cases (including 1983 ER-positive, and 1098 ER-negative) and 4687 controls from the African American Breast Cancer Epidemiology and Risk consortium, a collaborative project of four large studies of breast cancer in African American women (Carolina Breast Cancer Study, Black Women's Health Study, Women's Circle of Health Study, and Multiethnic Cohort). We used a multi-locus adaptive joint (AdaJoint) test to determine the association of each gene in the FGFR signaling pathway with overall breast cancer and ER subtypes. The FGF1 gene was significantly associated with risk of ER-negative breast cancer (P = 0.001). The FGFR2 gene was associated with risk of overall breast cancer (P = 0.002) and ER-positive breast cancer (P = 0.002). The FGF1 gene affects risk of ER-negative breast cancer in African American women. We confirmed the association of the FGFR2 gene with risk of overall and ER-positive breast cancer. These results highlight the importance of the FGFR signaling pathway in the pathogenesis of breast cancer, and suggest that different genes in the same pathway may be associated with different ER breast cancer subtypes. PMID:26743380

  20. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  1. Coupling between plate vibration and acoustic radiation

    NASA Technical Reports Server (NTRS)

    Frendi, Abdelkader; Maestrello, Lucio; Bayliss, Alvin

    1992-01-01

    A detailed numerical investigation of the coupling between the vibration of a flexible plate and the acoustic radiation is performed. The nonlinear Euler equations are used to describe the acoustic fluid while the nonlinear plate equation is used to describe the plate vibration. Linear, nonlinear, and quasi-periodic or chaotic vibrations and the resultant acoustic radiation are analyzed. We find that for the linear plate response, acoustic coupling is negligible. However, for the nonlinear and chaotic responses, acoustic coupling has a significant effect on the vibration level as the loading increases. The radiated pressure from a plate undergoing nonlinear or chaotic vibrations is found to propagate nonlinearly into the far-field. However, the nonlinearity due to wave propagation is much weaker than that due to the plate vibrations. As the acoustic wave propagates into the far-field, the relative difference in level between the fundamental and its harmonics and subharmonics decreases with distance.

  2. A new plate boundary in the Ionian Sea

    NASA Astrophysics Data System (ADS)

    Polonia, Alina; Torelli, Luigi; Artoni, Andrea; Bortoluzzi, Giovanni; Faccenna, Claudio; Ferranti, Luigi; Gasperini, Luca; Govers, Rob; Monaco, Carmelo; Neri, Giancarlo; Orecchio, Barbara; Rinus Wortel, M. J.

    2014-05-01

    segment in the Ionian Sea, connecting the compressive belt in northern Sicily to the Hellenic Arc system and dissecting the CA subduction complex. This deformation zone accommodates differential movements of the Calabrian and the Peloritan portions of CA and can explain the NW-SE extension observed in the straits of Messina as well as the relative motion between Calabria and NE Sicily. This reconstruction is in agreement with geodetic data and earthquake slip vectors observations which suggest the existence of a microplate in the central Mediterranean. The discontinuity between the two lobes would thus represent a major component of the southwestern (hitherto poorly constrained) boundary of this microplate. The motion of Africa relative to Eurasia would be accommodated along this structure by relative rotations between the different blocks resulting from African plate fragmentation.

  3. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (Inventor)

    1984-01-01

    An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.

  4. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  5. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  6. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  7. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  8. 49 CFR 236.779 - Plate, top.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Plate, top. 236.779 Section 236.779 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top....

  9. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  10. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  11. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  12. 49 CFR 213.123 - Tie plates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Tie plates. 213.123 Section 213.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.123 Tie plates. (a) In Classes 3 through 5...

  13. African mining

    SciTech Connect

    Not Available

    1987-01-01

    This book contains papers presented at a conference addressing the development of the minerals industry in Africa. Topics covered include: A review - past, present and future - of Zimbabwe's mining industry; Geomorphological processes and related mineralization in Tanzania; and Rock mechanics investigations at Mufulira mine, Zambia.

  14. INTERFACING INFANT MENTAL HEALTH KNOWLEDGE SYSTEMS: REFLECTIONS ON THE NARRATIVES OF LAY HOME VISITORS' EXPERIENCES OF LEARNING AND APPLYING RELATIONAL CONCEPTS OF DEVELOPMENT IN A SOUTH AFRICAN INTERVENTION PROGRAM.

    PubMed

    Baradon, Tessa; Bain, Katherine

    2016-07-01

    The question of interfacing research and clinically generated knowledge in the field of infant mental health (IMH) with local cultural knowledge and belief systems has provoked extended discussion in recent years. This article explores convergences and divergences between current research-based, relational IMH mental health models and "community" knowledge held by a group of South African lay home visitors from a socioeconomically deprived township. These women were trained in a psychoanalytic and attachment-informed infant mental health program that promotes a relational model of infant development. They provide an intervention that supports high risk mother-infant relationships in the same locality. A two-tiered approach was taken to the analysis of the home visitor interviews and focused on the home visitors' constructed narratives of infant development posttraining as well as the personal impact of the training and work on the home visitors themselves. The study found that psychoanalytic and attachment-informed thinking about development makes sense to those operating within the local South African cultural context, but that the accommodation of this knowledge is a complex and challenging process. PMID:27186854

  15. Lee plate equations for electroded quartz crystal plates with the consideration of electrode density and stiffness.

    PubMed

    Wang, Ji; Chen, Guojun; Du, Jianke

    2008-02-01

    Lee plate equations for high-frequency vibrations of piezoelectric plates have been established and improved over the last decades with the sole objective of obtaining the accurate prediction of frequency and mode shapes to aid crystal resonator design. The latest improvement includes extra terms related to derivatives of the flexural displacement to adjust the accuracy and consider electrodes for practical applications. As part of the efforts to make the equations applicable for resonator design with the improved frequency accuracy and consideration of electrodes, we derived Lee plate equations for electroded plates by changing the integration limits in the dimension reduction procedure to signify the dominant role of the crystal plate. By modifying the density terms in plate equations to include the contribution of both electrode stiffness and density, the accuracy of the thickness-shear vibration frequency of electroded plates is improved for commonly used electrode materials. PMID:18334357

  16. African and non-African admixture components in African Americans and an African Caribbean population.

    PubMed

    Murray, Tanda; Beaty, Terri H; Mathias, Rasika A; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U; Watson, Harold R; Ruczinski, Ingo; Dunston, Georgia M; Barnes, Kathleen C

    2010-09-01

    Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r(2)=0.992, r(2)=0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on approximately 14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (F(ST)). We found AAs and ACs were closest genetically (F(ST)=0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, approximately 400 well-defined AIMs were just as good for detecting substructure as approximately 14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

  17. The African superswell

    NASA Technical Reports Server (NTRS)

    Nyblade, Andrew A.; Robinson, Scott W.

    1994-01-01

    Maps of residual bathymetry in the ocean basins around the African continent reveal a broad bathymetric swell in the southeastern Atlantic Ocean with an amplitude of about 500 m. We propose that this region of anomalously shallow bathymetry, together with the contiguous eastern and southern African plateaus, form a superswell which we refer to as the African superswell. The origin of the African superswell is uncertain. However, rifting and volcanism in eastern Africa, as well as heat flow measurements in southern Africa and the southeastern Atlantic Ocean, suggest that the superswell may be attributed, at least in part, to heating of the lithosphere.

  18. "Half plate of rice to a male casual sexual partner, full plate belongs to the husband": Findings from a qualitative study on sexual behaviour in relation to HIV and AIDS in northern Tanzania

    PubMed Central

    2011-01-01

    developed in close collaboration with affected communities and be closely related to policy-making and implementation; to go beyond the limited success of traditional behavioural and biomedical interventions to particularly address the underlying social and structural drivers of HIV risk and vulnerability in the study communities. PMID:22202562

  19. Differences between TB cases infected with M. africanum, West-African type 2, relative to Euro-American M. tuberculosis- an update

    PubMed Central

    de Jong, Bouke C; Adetifa, Ifedayo; Walther, Brigitte; Hill, Philip C; Antonio, Martin; Ota, Martin; Adegbola, Richard A

    2009-01-01

    M. africanum is a common cause of human pulmonary TB in West Africa. We previously described phenotypic differences between M. africanum and M. tuberculosis among 290 patients. In the present analysis we compared 692 TB patients infected with the two most common lineages within the M. tuberculosis complex found in the Gambia, namely M. africanum West African type 2 (39% prevalence) and Euro American M. tuberculosis (55% prevalence). We identified additional phenotypic differences between infections with these two organisms. M. africanum patients were more likely to be of older age and HIV infected. In addition, they had worse disease on chest x-ray, despite complaining of cough for equal duration, and were more likely severely malnourished. In this cohort the prevalence of M. africanum did not change significantly over a seven year period. PMID:20002176

  20. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  1. WFPDB: European Plate Archives

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Milcho

    2007-08-01

    The Wide-Field Plate Database (WFPDB) gives an inventory of all wide-field (>~ 1 sq. deg) photographic observations archived in astronomical institutions over the world. So it facilitates and stimulates their use and preservation as a valuable source of information for future investigations in astronomy. At present WFPDB manages plate-index information for 25% of all existing plates providing on-line access from Sofia (http://www.skyarchive.org/search) and in CDS, Strasbourg. Here we present the new development of WFPDB as an instrument for searching of long term brightness variations of different sky objects stressing on the European photographic plate collections (from existing 2 million wide-field plates more than 55% are in Europe: Germany, Russia, Ukraine, Italy, Czech Republic, etc.). We comment examples of digitization (with flatbed scanners) of the European plate archives in Sonneberg, Pulkovo, Asiago, Byurakan, Bamberg, etc. and virtual links of WFPDB with European AVO, ADS, IBVS.

  2. Spatial Structure and Climatic Adaptation in African Maize Revealed by Surveying SNP Diversity in Relation to Global Breeding and Landrace Panels

    PubMed Central

    Westengen, Ola T.; Berg, Paul R.; Kent, Matthew P.; Brysting, Anne K.

    2012-01-01

    Background Climate change threatens maize productivity in sub-Saharan Africa. To ensure food security, access to locally adapted genetic resources and varieties is an important adaptation measure. Most of the maize grown in Africa is a genetic mix of varieties introduced at different historic times following the birth of the trans-Atlantic economy, and knowledge about geographic structure and local adaptations is limited. Methodology A panel of 48 accessions of maize representing various introduction routes and sources of historic and recent germplasm introductions in Africa was genotyped with the MaizeSNP50 array. Spatial genetic structure and genetic relationships in the African panel were analysed separately and in the context of a panel of 265 inbred lines representing global breeding material (based on 26,900 SNPs) and a panel of 1127 landraces from the Americas (270 SNPs). Environmental association analysis was used to detect SNPs associated with three climatic variables based on the full 43,963 SNP dataset. Conclusions The genetic structure is consistent between subsets of the data and the markers are well suited for resolving relationships and admixture among the accessions. The African accessions are structured in three clusters reflecting historical and current patterns of gene flow from the New World and within Africa. The Sahelian cluster reflects original introductions of Meso-American landraces via Europe and a modern introduction of temperate breeding material. The Western cluster reflects introduction of Coastal Brazilian landraces, as well as a Northeast-West spread of maize through Arabic trade routes across the continent. The Eastern cluster most strongly reflects gene flow from modern introduced tropical varieties. Controlling for population history in a linear model, we identify 79 SNPs associated with maximum temperature during the growing season. The associations located in genes of known importance for abiotic stress tolerance are

  3. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  4. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  5. CALUTRON FACE PLATE

    DOEpatents

    Brobeck, W.M.

    1959-08-25

    The construction of a removable cover plate for a calutron tank is described. The plate is fabricated of a rectangular frame member to which is welded a bowed or dished plate of thin steel, reinforced with transverse stiffening ribs. When the tank is placed between the poles of a magnet, the plate may be pivoted away from the tank and magnet and is adapted to support the ion separation mechanism secured to its inner side as well as the vacuum load within the tank.

  6. PLATES WITH OXIDE INSERTS

    DOEpatents

    West, J.M.; Schumar, J.F.

    1958-06-10

    Planar-type fuel assemblies for nuclear reactors are described, particularly those comprising fuel in the oxide form such as thoria and urania. The fuel assembly consists of a plurality of parallel spaced fuel plate mennbers having their longitudinal side edges attached to two parallel supporting side plates, thereby providing coolant flow channels between the opposite faces of adjacent fuel plates. The fuel plates are comprised of a plurality of longitudinally extending tubular sections connected by web portions, the tubular sections being filled with a plurality of pellets of the fuel material and the pellets being thermally bonded to the inside of the tubular section by lead.

  7. Development of West African Rainy Seasons (Invited)

    NASA Astrophysics Data System (ADS)

    Cook, K. H.

    2013-12-01

    The development of West African rainy seasons in the observed climatology can be understood in terms of two factors: continentality, i.e., the shape and placement of the African continent, and solar forcing. First, the observed features of the West African spring and summer precipitation climatology that distinguish it from the precipitation climatology of the tropical Atlantic to the east and Central/Eastern Africa to the west are presented. These include a lingering of the precipitation maximum along the Guinean coast in June and the apparent sudden movement of the precipitation maximum into the Sahel in early July. Then, these distinguishing features of the West Africa precipitation climatology are explained in terms of the regional dynamics and, finally, related to continentality and solar forcing through the roles of the African easterly jet, land surface temperature, and seasonally-varying SSTs.

  8. [West African childbirth traditions].

    PubMed

    Hallgren, R

    1983-11-01

    Religious and medical practices are steeped in the traditions of West African culture vis-a-vis childbirth. It is customary for delivery to occur with the woman squatting on the ground surrounded by sisters and female relatives, some of whom function as midwives. Midwives get paid only if delivery is successful. A stool is also often used in childbirth. The name given to a child in the Yoruba tribe in Nigeria has to refer to the circumstances of the individual's birth. The contact with the earth (as in the squatting position) has religious overtones--it indicates the fecundity of the earth, and the mother's contact with it. Infertility is considered the greatest tragedy in traditional African society. In Senegal, a childless woman pays a fertile one a certain sum in return for bearing her a child who would be raised as her own (this tradition is not unlike surrogate motherhood in Western countries). Men are never present at birth; however, in urban settings this practice is changing. The burial of the placenta and umbilical cord is thought to restore the woman's fertility and help heal her womb. This practice was even recorded in 19th century Sweden harkening back to heathen times. In Ghana, an infertile woman urinates on the ground where the placenta is buried in the belief that her fertility will be restored. The birth of twins is regarded as a great blessing, and as a sign of fertility; however, the inability of the mother to breast-feed both twins may result in the death of the weaker child. The harmony of nature, animals, and human beings is paramount in traditional West Africa religion and life, and undoubtedly Western culture could learn from some of these beliefs. PMID:6558064

  9. Addressing Reading Underachievement in African American Boys through a Multi-Contextual Approach

    ERIC Educational Resources Information Center

    Husband, Terry

    2012-01-01

    Much has been written about reading disparities between African American males and other student groups. Interestingly, the majority of this scholarship focuses on African American males at preadolescent states of development and beyond. To date, relatively little has been documented relative to improving reading outcomes in African American males…

  10. 22 CFR 1508.635 - May the African Development Foundation settle a debarment or suspension action?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true May the African Development Foundation settle a debarment or suspension action? 1508.635 Section 1508.635 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION... Actions § 1508.635 May the African Development Foundation settle a debarment or suspension action? Yes,...

  11. 22 CFR 1508.635 - May the African Development Foundation settle a debarment or suspension action?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 true May the African Development Foundation settle a debarment or suspension action? 1508.635 Section 1508.635 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION... Actions § 1508.635 May the African Development Foundation settle a debarment or suspension action? Yes,...

  12. 22 CFR 1508.635 - May the African Development Foundation settle a debarment or suspension action?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 2 2012-04-01 2009-04-01 true May the African Development Foundation settle a debarment or suspension action? 1508.635 Section 1508.635 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION... Actions § 1508.635 May the African Development Foundation settle a debarment or suspension action? Yes,...

  13. 22 CFR 1508.635 - May the African Development Foundation settle a debarment or suspension action?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false May the African Development Foundation settle a debarment or suspension action? 1508.635 Section 1508.635 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION... Actions § 1508.635 May the African Development Foundation settle a debarment or suspension action? Yes,...

  14. 22 CFR 1508.635 - May the African Development Foundation settle a debarment or suspension action?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 true May the African Development Foundation settle a debarment or suspension action? 1508.635 Section 1508.635 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION... Actions § 1508.635 May the African Development Foundation settle a debarment or suspension action? Yes,...

  15. The World Is Waiting for the Sunrise: African Americans "yel Mundo Latino."

    ERIC Educational Resources Information Center

    Widener, Danny

    1998-01-01

    Traces the long and varied history of interaction and collective action by African Americans and Latinos, focusing on common culture and political cooperation. Outlines issues related to the continued cooperation of African Americans and Latinos, and common political projects. (SLD)

  16. 16 Extraordinary African Americans.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    This collection for children tells the stories of 16 African Americans who helped make America what it is today. African Americans can take pride in the heritage of these contributors to society. Biographies are given for the following: (1) Sojourner Truth, preacher and abolitionist; (2) Frederick Douglass, abolitionist; (3) Harriet Tubman, leader…

  17. African Studies Computer Resources.

    ERIC Educational Resources Information Center

    Kuntz, Patricia S.

    African studies computer resources that are readily available in the United States with linkages to Africa are described, highlighting those most directly corresponding to African content. Africanists can use the following four fundamental computer systems: (1) Internet/Bitnet; (2) Fidonet; (3) Usenet; and (4) dial-up bulletin board services. The…

  18. African Literature as Celebration.

    ERIC Educational Resources Information Center

    Achebe, Chinua

    1989-01-01

    Describes the Igbo tradition of "Mbari," a communal creative enterprise that celebrates the world and the life lived in it through art. Contrasts the cooperative, social dimension of pre-colonial African culture with the exclusion and denial of European colonialism, and sees new African literature again celebrating human presence and dignity. (AF)

  19. Educating African American Males

    ERIC Educational Resources Information Center

    Bell, Edward E.

    2010-01-01

    Background: Schools across America spend money, invest in programs, and sponsor workshops, offer teacher incentives, raise accountability standards, and even evoke the name of Obama in efforts to raise the academic achievement of African American males. Incarceration and college retention rates point to a dismal plight for many African American…

  20. Africans Away from Home.

    ERIC Educational Resources Information Center

    Clarke, John Henrik

    Africans who were brought across the Atlantic as slaves never fully adjusted to slavery or accepted its inevitability. Resistance began on board the slave ships, where many jumped overboard or committed suicide. African slaves in South America led the first revolts against tyranny in the New World. The first slave revolt in the Caribbean occurred…

  1. Keeping African Masks Real

    ERIC Educational Resources Information Center

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  2. Empty plates and larger waists: a cross-sectional study of factors associated with plate clearing habits and body weight.

    PubMed

    Robinson, E; Hardman, C A

    2016-06-01

    Clearing one's plate out of habit when eating may promote excess energy consumption. This study examined whether plate clearing is related to increased body weight in a sample of young adults. It also sought to identify potential determinants of plate clearing. A cross-sectional design was used in which 385 young adults from a UK university completed self-report measures of plate clearing, weight and height, and demographic characteristics. Plate clearing was predictive of heavier body weight in both unadjusted and adjusted analyses. Parental encouragement to clear one's plate during childhood (retrospectively reported) and personal concerns about food waste were both independent predictors of plate clearing tendencies. Clearing one's plate when eating is associated with heavier body weight, and the prevalence of this behaviour may depend on parenting practices and concerns about food waste. Further work examining the longitudinal effect of plate clearing on weight gain is now needed. PMID:26695723

  3. Identification and characterisation of vaginal lactobacilli from South African women

    PubMed Central

    2013-01-01

    Background Bacterial vaginosis (BV), which is highly prevalent in the African population, is one of the most common vaginal syndromes affecting women in their reproductive age placing them at increased risk for sexually transmitted diseases including infection by human immunodeficiency virus-1. The vaginal microbiota of a healthy woman is often dominated by the species belonging to the genus Lactobacillus namely L. crispatus, L. gasseri, L. jensenii and L. iners, which have been extensively studied in European populations, albeit less so in South African women. In this study, we have therefore identified the vaginal Lactobacillus species in a group of 40 African women from Soweto, a township on the outskirts of Johannesburg, South Africa. Methods Identification was done by cultivating the lactobacilli on Rogosa agar, de Man-Rogosa-Sharpe (MRS) and Blood agar plates with 5% horse blood followed by sequencing of the 16S ribosomal DNA. BV was diagnosed on the basis of Nugent scores. Since some of the previous studies have shown that the lack of vaginal hydrogen peroxide (H2O2) producing lactobacilli is associated with bacterial vaginosis, the Lactobacillus isolates were also characterised for their production of H2O2. Results Cultivable Lactobacillus species were identified in 19 out of 21 women without BV, in three out of five women with intermediate microbiota and in eight out of 14 women with BV. We observed that L. crispatus, L. iners, L. jensenii, L. gasseri and L. vaginalis were the predominant species. The presence of L. crispatus was associated with normal vaginal microbiota (P = 0.024). High level of H2O2 producing lactobacilli were more often isolated from women with normal microbiota than from the women with BV, although not to a statistically significant degree (P = 0.064). Conclusion The vaginal Lactobacillus species isolated from the cohort of South African women are similar to those identified in European populations. In accordance with the other

  4. Effect of the Reunion plume head on Indo-Atlantic plate motions: evidence from the bend along the Southwest Indian ridge fracture zones

    NASA Astrophysics Data System (ADS)

    Cande, S. C.; Stegman, D. R.; Patriat, P.

    2011-12-01

    It was recently shown that the arrival at the Earth's surface of the Reunion plume head had a major effect on the motions of the Indo-Atlantic plates between 68 and 45 Ma (Cande and Stegman, 2011). The primary evidence for this is the observation that the motions of the Indian and African plates appear to have been coupled during this period: when the Indian plate speeds up between 68 and 66 Ma (from 80 to 180 mm/yr relative to Africa), the convergence of Africa with Eurasia slows down and perhaps stops, and when the Indian plate slows down between 52 and 45 Ma, Africa-Eurasia convergence speeds up. The fast motion of India relative to Africa is well documented by seafloor spreading anomalies and can be divided into three stages: 1) between 66 and 63 Ma, corresponding to the formation of the Deccan traps, when India moves superfast (roughly 180 mm/yr), 2) between 63 and 52 Ma when the speed of India is roughly 100 mm/yr, which is fast but not superfast, and 3) between 52 and 45 Ma when India's motion gradually slows from 100 to 40 mm/yr. The changes in Africa's motion are best recorded in the systematic "swings" of the Euler stage poles constraining the motion of Africa relative to North America, South America and Antarctica. The stage poles (relative to Africa) on all three plate pairs move along arcs first away from and then back towards the Africa-Eurasia Euler pole, constraining a major slowdown of the African plate relative to Eurasia which reaches its nadir between 57 and 53 Ma before returning to its pre-slowdown motion around 45 Ma. The systematic slowing and speedup of Africa is recorded in the great bends of the fracture zones in the Central Atlantic, South Atlantic and Southwest Indian ridges. Since the Indian and African plates were on opposite sides of the Reunion plume relative to Eurasia, the synchroneity of the plate motion changes strongly suggests that the plume head was a major driving force and, in particular, that the slow down of India between

  5. Diabetes in African Americans

    PubMed Central

    Marshall, M

    2005-01-01

    African Americans have a high risk for type 2 diabetes. Genetic traits, the prevalence of obesity, and insulin resistance all contribute to the risk of diabetes in the African American community. African Americans have a high rate of diabetic complications, because of poor glycaemic control and racial disparities in health care in the USA. African Americans with diabetes may have an atypical presentation that simulates type 1 diabetes, but then their subsequent clinical course is typical of type 2 diabetes. Culturally sensitive strategies, structured disease management protocols, and the assistance of nurses, diabetic educators, and other health care professionals are effective in improving the outcome of diabetes in the African American community. PMID:16344294

  6. Range and Frequency of Africanized Honey Bees in California (USA)

    PubMed Central

    Kono, Yoshiaki; Kohn, Joshua R.

    2015-01-01

    Africanized honey bees entered California in 1994 but few accounts of their northward expansion or their frequency relative to European honey bees have been published. We used mitochondrial markers and morphometric analyses to determine the prevalence of Africanized honeybees in San Diego County and their current northward progress in California west of the Sierra Nevada crest. The northernmost African mitotypes detected were approximately 40 km south of Sacramento in California’s central valley. In San Diego County, 65% of foraging honey bee workers carry African mitochondria and the estimated percentage of Africanized workers using morphological measurements is similar (61%). There was no correlation between mitotype and morphology in San Diego County suggesting Africanized bees result from bidirectional hybridization. Seventy percent of feral hives, but only 13% of managed hives, sampled in San Diego County carried the African mitotype indicating that a large fraction of foraging workers in both urban and rural San Diego County are feral. We also found a single nucleotide polymorphism at the DNA barcode locus COI that distinguishes European and African mitotypes. The utility of this marker was confirmed using 401 georeferenced honey bee sequences from the worldwide Barcode of Life Database. Future censuses can determine whether the current range of the Africanized form is stable, patterns of introgression at nuclear loci, and the environmental factors that may limit the northern range of the Africanized honey bee. PMID:26361047

  7. African bees to control African elephants

    NASA Astrophysics Data System (ADS)

    Vollrath, Fritz; Douglas-Hamilton, Iain

    2002-11-01

    Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

  8. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  9. Earthquakes and plate tectonics

    USGS Publications Warehouse

    Spall, H.

    1977-01-01

    An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

  10. Post-Messinian evolutionary relationships across the Sicilian channel: Mitochondrial and nuclear markers link a new green toad from Sicily to African relatives

    PubMed Central

    2008-01-01

    Background Little attention has been paid to the consequences of the last landbridge between Africa and Sicily on Mediterranean biogeography. Previous paleontological and scarce molecular data suggest possible faunal exchange later than the well-documented landbridge in the Messinian (5.3 My); however, a possible African origin of recent terrestrial Sicilian fauna has not been thoroughly tested with molecular methods. To gain insight into the phylogeography of the region, we examine two mitochondrial and two nuclear markers (one is a newly adapted intron marker) in green toads (Bufo viridis subgroup) across that sea barrier, the Strait of Sicily. Results Extensive sampling throughout the western Mediterranean and North Africa revealed a deep sister relationship between Sicilian (Bufo siculus n.sp.) and African green toads (B. boulengeri) on the mitochondrial and nuclear level. Divergence times estimated under a Bayesian-coalescence framework (mtDNA control region and 16S rRNA) range from the Middle Pliocene (3.6 My) to Pleistocene (0.16 My) with an average (1.83 to 2.0 My) around the Pliocene/Pleistocene boundary, suggesting possible land connections younger than the Messinian (5.3 My). We describe green toads from Sicily and some surrounding islands as a new endemic species (Bufo siculus). Bufo balearicus occurs on some western Mediterranean islands (Corsica, Sardinia, Mallorca, and Menorca) and the Apennine Peninsula, and is well differentiated on the mitochondrial and nuclear level from B. siculus as well as from B. viridis (Laurenti), whose haplotype group reaches northeastern Italy, north of the Po River. Detection of Calabrian B. balearicus haplotypes in northeastern Sicily suggests recent invasion. Our data agree with paleogeographic and fossil data, which suggest long Plio-Pleistocene isolation of Sicily and episodic Pleistocene faunal exchange across the Strait of Messina. It remains unknown whether both species (B. balearicus, B. siculus) occur in

  11. The 894T allele of endothelial nitric oxide synthase gene is related to left ventricular mass in African Americans with high-normal blood pressure.

    PubMed Central

    Lapu-Bula, Rigobert; Quarshie, Alexander; Lyn, Deborah; Oduwole, Adefisayo; Pack, Cheryl; Morgan, Jan; Nkemdiche, Sunday; Igho-Pemu, Priscilla; Onwuanyi, Anekwe; Li, Rongling; Ofili, Elizabeth

    2005-01-01

    BACKGROUND AND OBJECTIVES: The 894T allele in exon 7 of the endothelial nitric oxide synthase (eNOS) gene has been inconsistently associated with hypertension in different racial groups. Because high-normal blood pressure (BP) confers an increased risk for the development of hypertension and other cardiovascular disorders, including left ventricular hypertrophy (LVH), we tested the hypothesis that the allelic variation (894T) in the eNOS gene would directly correlate with alterations in LV mass (LVM) in individuals with high-normal BP. METHODS: Genotype distribution of G894T was compared between 20 African Americans (10 females/10 males) with high-normal BP (systolic BP of 130-139 and/or diastolic BP of 85-89 mmHg) and 64 counterparts (37 females/27 males) with normal BP (<130/85 mmHg). Echocardiographic LVM was calculated (Devereux formula) and indexed to body surface area to define the presence of LVH (LVMI >134/110 g/m2 for men/women). RESULTS: For the entire group, the 894T allelic frequencies (15, 48%) and G894T genotype distributions were consistent with the Hardy-Weinberg equilibrium expectations (estimated disequilibrium coefficient = 0.0118, P=0.40). LVMI was significantly higher in homozygous carriers (TT) of the rare 894T allele (n = 3 females/0 males) than in heterozygous GT (n = 13 females/7 males) and individuals bearing the GG (n=34 females/27 males) variant (124 +/- 70 vs. 82 +/- 24 and 82 +/- 19 g/m2, respectively, P < 0.05). The observed relationship between eNOS 894T allele and LVMI was restricted to individuals with high-normal BP (r = 0.94, P = 0.03) but not in those with normal BP (r = 0.39, P =0.64), by analysis of variance (ANOVA) after adjusting for age, gender, body mass index, smoking and systolic BP. CONCLUSION: These findings, not previously described, provide important preliminary evidence to suggest an increased susceptibility to LVH in African Americans who carry the 894T variant of the eNOS gene and have high-normal blood pressure

  12. Plate-induced Miocene extension in southern California

    SciTech Connect

    Stuart, W.D. Univ. of California, Santa Barbara, CA )

    1992-01-01

    Miocene crustal extension in southern California can be explained by the interaction of tectonic plates in relative motion. The Pacific, Juan de Fuca, and Farallon (Guadalupe) plates are represented by flat elastic plates surrounded by an infinite elastic plate, the eastern part of which represents the North America plate. Forcing is by assigned subduction pull, and tractions at all plate boundaries satisfy a viscous constitutive law. Plate bottoms are stress-free. In the first part of the solution plate velocities and boundary tractions are found from static equilibrium. Then principal horizontal stresses and strains in plate interiors caused by tractions and subduction pull are found by a boundary element procedure. Using plate boundary geometry from Stock and Hodges for early- and mid-Miocene times, it is found that the portion of the North America plate margin between the Mendocino and Rivera triple junctions has maximum extensional strain directed westward. This result is generally consistent with directions associated with metamorphic core complex formation in southern California. The model is also consistent with extensional strain and rotation sense of crustal blocks in the vicinity of Los Angeles, as inferred by Luyendyk and others from paleomagnetic data. In the model the greatest extensional strain of the North America plate occurs near the Pacific-North America transform, in the area above the absent Farallon slab. Extension direction varies from northwest to southwest according to plate geometry, subduction pull (Juan de Fuca and Guadalupe), and plate boundary tractions.

  13. Turbine vane plate assembly

    DOEpatents

    Schiavo Jr., Anthony L.

    2006-01-10

    A turbine vane assembly includes a turbine vane having first and second shrouds with an elongated airfoil extending between. Each end of the airfoil transitions into a shroud at a respective junction. Each of the shrouds has a plurality of cooling passages, and the airfoil has a plurality of cooling passages extending between the first and second shrouds. A substantially flat inner plate and an outer plate are coupled to each of the first and second shrouds so as to form inner and outer plenums. Each inner plenum is defined between at least the junction and the substantially flat inner plate; each outer plenum is defined between at least the substantially flat inner plate and the outer plate. Each inner plenum is in fluid communication with a respective outer plenum through at least one of the cooling passages in the respective shroud.

  14. Diurnal and intra-urban particle concentrations in relation to windspeed and stability during the dry season in three African cities.

    PubMed

    Eliasson, I; Jonsson, P; Holmer, B

    2009-07-01

    The spatial and temporal variations of PM(2.5), PM(10) and TSP in three African cities of different sizes (Dar es Salaam, Ouagadougou and Gaborone) were investigated using portable particle counters. Three different areas (downtown, green residential and traditional residential) and a reference site were designated in each of the cities in order to detect intra-urban and temporal variability. Morning, noon and night measurements were conducted in the urban areas while observations at reference stations were made continuously over the field periods. A clear diurnal pattern in particle concentrations was found in inland Gaborone and Ouagadougou, with morning and night peaks where the latter was the highest. However, in coastal Dar es Salaam the night peak was almost absent due to delayed stabilisation of the air. Particle concentrations at the Ouagadougou reference station were extreme. The direct contribution of vehicle emissions are of secondary importance since the PM(2.5)/PM(10) ratios are low (0.1-0.3). Much of the particles are supposed to be soil particles that are entrained in the air by daytime high windspeeds followed by nighttime subsidence as the air is stabilised and windspeed decreases. However, in all three cities, resuspension are important as areas with a network of unpaved roads showed the highest concentrations of suspended particles. Generally, the central business district had the lowest concentrations of particulate matter. PMID:18607763

  15. Incarceration history relative to health, substance use, and violence in a sample of vulnerable South African women: implications for health services in criminal justice settings

    PubMed Central

    Johnson, Jennifer E; Carney, Tara; Kline, Tracy; Browne, Felicia A; Wechsberg, Wendee M

    2012-01-01

    International research has suggested that women in the criminal justice system carry a higher burden of many illnesses than women in the community, especially mental health disorders, substance use disorders, sexually transmitted infections, and a history of violent victimization. Knowledge of these health disparities is often used to advocate for relevant screening and treatment services for women passing through criminal justice custody within US and European settings. However, almost all criminal justice health research has taken place in high-income countries, with little or no research taking place in other countries, especially in South Africa. This baseline analysis compares the health, substance use, and violent victimization of women who have ever been incarcerated to those who have not, in a cross-sectional sample of 720 young, vulnerable, substance-using women in Cape Town, South Africa. Results of univariate tests indicated that women who had ever been incarcerated had worse health, mental health, and sexually transmitted infection indicators and were more likely to report use of substances and to have been victims of physical and sexual assault than women who had never been incarcerated. Passing through the criminal justice system appears to be a marker for a variety of current and/or future health service needs among vulnerable South African women, suggesting that screening, prevention, and treatment referral efforts at the time of intersection with the criminal justice system may reduce health burden for these women. PMID:24474876

  16. Variability in the egg production rates of the calanoid copepod, Pseudodiaptomus hessei in a South African estuary in relation to environmental factors

    NASA Astrophysics Data System (ADS)

    Noyon, Margaux; William Froneman, P.

    2013-12-01

    The importance of physical parameters (temperature and salinity) and seston composition (chlorophyll a, protein, carbohydrate and lipid concentration as well as fatty acid composition) in controlling the in situ egg productions rate (EPR) of the calanoid copepod, Pseudodiaptomus hessei, was investigated monthly in a permanently open South African estuary over a one year period. The EPR of P. hessei ranged from 3.00 to 37.23 eggs F-1 d-1 and were amongst the highest rates published for egg-carrying copepods. EPR varied significantly between months while hatching success was constant and high throughout the study period (91% on average). A stepwise multiple linear regression selected temperature - Chl a 2-20 μm size fraction and temperature - 16:1(n-7) as the best descriptors of EPR (R2 = 0.86) and nauplii production (R2 = 0.92), respectively. The maximum values of EPR were recorded in September and December, following freshwater inflow into the estuary. September had an extremely high level of Chl a while December showed only an average level. We suggest that the EPR of P. hessei is also influenced by indirect effect of freshwater input into the estuary. The freshwater input modified the nutrient concentration and composition and as such altered the fatty acid seston composition which enhanced the EPR.

  17. Spiral Plate Method for Bacterial Determination

    PubMed Central

    Gilchrist, J. E.; Campbell, J. E.; Donnelly, C. B.; Peeler, J. T.; Delaney, J. M.

    1973-01-01

    A method is described for determining the number of bacteria in a solution by the use of a machine which deposits a known volume of sample on a rotating agar plate in an ever decreasing amount in the form of an Archimedes spiral. After the sample is incubated, different colony densities are apparent on the surface of the plate. A modified counting grid is described which relates area of the plate of volume of sample. By counting an appropriate area of the plate, the number of bacteria in the sample is estimated. This method was compared to the pour plate procedure with the use of pure and mixed cultures in water and milk. The results did not demonstrate a significant difference in variance between duplicates at the α = 0.01 level when concentrations of 600 to 12 × 105 bacteria per ml were used, but the spiral plate method gave counts that were higher than counts obtained by the pour plate method. The time and materials required for this method are substantially less than those required for the conventional aerobic pour plate procedure. Images PMID:4632851

  18. Some growth points in African child development research.

    PubMed

    Serpell, Robert; Marfo, Kofi

    2014-01-01

    We reflect on ways in which research presented in earlier chapters responds to challenges of generating an African child development field and identify additional issues calling for the field's attention. The chapters collectively display a variety of African contexts and reflexive evidence of the authors' African cultural roots. Connecting research with African audiences demands cooperative communication between educational practitioners and parents with low literacy, and cross-sector communication among professionals. Intracultural exploration of factors influencing the pattern of human development has begun to document the potential of indigenous African cultures as a fund of resources for enhancing child development. Priority topics for future African developmental research include multilingualism, musical performance, socially distributed caregiving, and the relation between adolescence and economic activity. Integration of multiple disciplines in the application of research-based principles to service delivery in the fields of community-based (re)habilitation and early childhood care and education calls for researcher collaboration with practitioners. PMID:25512048

  19. African American women and breastfeeding: an integrative literature review.

    PubMed

    Spencer, Becky S; Grassley, Jane S

    2013-07-01

    The purpose of this article is to present a review of literature regarding factors that influence breastfeeding intentions, initiation, and duration in the African American population. Research related to health disparities experienced by African Americans in the United States, as well as research regarding the protective benefits of breastfeeding for those specific health disparities, are also presented. Community and institutional interventions and promotional campaigns aimed at increasing initiation and duration of breastfeeding in the African American population are discussed. Future research regarding African American women's breastfeeding experiences using Black feminist thought as a theoretical foundation is recommended. PMID:23445372

  20. Absolute plate velocities from seismic anisotropy: Importance of correlated errors

    NASA Astrophysics Data System (ADS)

    Zheng, Lin; Gordon, Richard G.; Kreemer, Corné

    2014-09-01

    The errors in plate motion azimuths inferred from shear wave splitting beneath any one tectonic plate are shown to be correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. Our preferred set of angular velocities, SKS-MORVEL, is determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25 ± 0.11° Ma-1 (95% confidence limits) right handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ = 19.2°) differs insignificantly from that for continental lithosphere (σ = 21.6°). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ = 7.4°) than for continental lithosphere (σ = 14.7°). Two of the slowest-moving plates, Antarctica (vRMS = 4 mm a-1, σ = 29°) and Eurasia (vRMS = 3 mm a-1, σ = 33°), have two of the largest within-plate dispersions, which may indicate that a plate must move faster than ≈ 5 mm a-1 to result in seismic anisotropy useful for estimating plate motion. The tendency of observed azimuths on the Arabia plate to be counterclockwise of plate motion may provide information about the direction and amplitude of superposed asthenospheric flow or about anisotropy in the lithospheric mantle.